ALBERT

Description: Voorjaar 1949 ontving ik een kleine collectie levende vissen uit Suriname (Nederlands Guiana), door een zeeman verzameld in een poel nabij Paramaribo. Helaas is de juiste vindplaats niet nader aangegeven, dan enige kilometers ten zuiden van de hoofdstad.\nOnmiddellijk na ontvangst werden de vissen, die hier het onderwerp van bespreking zijn, in een groot gezelschapsaquarium (150 X 60 X 50 cm. hoog) ondergebracht, dat reeds werd bevolkt door verscheidene Nannostomini, Hasemania marginata, Rivulus cylindraceus, Acanthophthalmus kuhli, Dermogenus pusillus en Nannacara anomala en N. taenia.

Description: The increased importance which the European red mite (Paratetranychus pilosus (Can. et Fanz.)) (= Metatetranychus ulmi (Koch)) has assumed in recent years has led to an intensive study of its biology and natural history.\nIn the course of these investigations many workers, and in particular those in Nova Scotia (vide Lord, 1949), have become convinced that this pest can be controlled, on apple trees at least, by natural means and that some of the most active agents in its eradication are the representatives of that group of predaceous mites which Vitzthum (1941) placed in the subfamily Phytoseiinae Ber\'lese, 1916 1). As the late Dr. A. C. Oudemans of Arnhem included many if not most of these species in the genus Typhlodromus as he conceived it, this paper is in essence a revision of that genus.\nPresumably because of their small size and limited distribution, which is largely contingent upon readily available populations of their hosts, little attention has been paid to these predators from either the ecological or taxonomic point of view. A cursory survey of the literature pertaining to the predaceous relationship which exists between the Phytoseiinae herein to be discussed and the tetranychid mites may serve as an appraisal of this economically significant group of mites. Koch (1839) in describing what now appears to be a typhlodromid, viz., Gamasus vepallidus, made no reference to its possible predaceous habits. Scheuten (1857) thought that the eriophyids which he found associated in numbers with his Typhlodromus pyri were its offspring. Berlese (1882-1898), however, had a better understanding of these relationships and was able to state in his redescription of G. vepallidus as Seius (Seiulus) vepallidus (K.) that it was a predator of small acari as well as being a mycophage. His countryman, Ribaga (1902), writing of the

Description: CONTENTS\nIntroduction............... 3\nSystematic survey of the Limacidae of the central and western Canary Islands 5 Biogeographical notes on the Limacidae of the Canary Islands . . . . 21 Alphabetical list of the persons who collected or observed Limacidae in the Canary Islands.............. 31\nLiterature............... 32\nINTRODUCTION\nIn the spring of 1947 I was so fortunate as to join for some 9 weeks the Danish Zoological Expedition to the Canary Islands. During my stay I collected materials for the Rijksmuseum van Natuurlijke Historie at Leiden, paying special attention to the land- and freshwater Mollusca. This paper contains the first results of the examination of the Mollusca collected.\nMy Danish friends Dr. Gunnar Thorson and Dr. Helge Vols\xc3\xb8e generously put at my disposal the non-marine Mollusca they collected during their stay in the Canaries. When the material has been worked up, duplicates will be deposited in the Zoological Museum at Copenhagen.\nI am indebted to several persons who helped me in various ways in the investigations here published. Prof. Dr. N. Hj. Odhner (Stockholm) very kindly put at my disposal a MS list of all the Mollusca of the Canary Islands and their distribution, which he had compiled for private use. Mr. Hugh Watson (Cambridge) never failed to help me by examining or lending specimens, and in detailed letters gave me the benefit of his great experience.\nDuring my stay in Paris in March 1950 Dr. G. Ranson and Dr. A. Franc put at my disposal for examination the Canarian slugs present in the Mus\xc3\xa9um

Description: The present paper is an extension of my revision of the Malaysian species of the genus Dillenia L. (Wormia Rottb. included) inserted in the revision of the Dilleniaceae in the Flora Malesiana ser. I, vol. 4, part 3, pp. 141\xe2\x80\x94174, published in December 1951. A critical revision of the whole genus has never been published before; the unfortunate result of this has been that the delimitation of Dillenia and Wormia, usually as distinct genera, has been based on different characters by various authors. The extension of the revision for the Flora Malesiana so as to include the extra-malaysian species enabled me to study a number of species, the knowledge of which certainly confirmed me in my idea that the characters on which Dillenia and Wormia had been separated before are certainly not the primary characters, to be used in the taxonomic treatment of the genus.\nAll specimens and literature mentioned in this work have been examined by me, unless indicated otherwise; excepted are the specimens of the U.S. National Herbarium., of which I have only examined those collections, of which no duplicates were available from other herbaria. Particulars, not to be taken from the herbarium specimens themselves, such as habit, height, diameter, colour, etc., have been taken from the collectors\xe2\x80\x99 notes and, as far as reliable, from the literature, and are inserted in the descriptions; if there are contradictory data, they are discussed under the Notes.

Description: Exbucklandia R. W. Brown ( Bucklandia R. Br. non Pr. ex Sternb., Symingtonia Steen.) In an article on \xe2\x80\x9cAlterations in some fossil and living floras\xe2\x80\x9d (J. Wash. Ac. Sc. 36: 348. Oct. 1946) R. W. Brown proposed the new generic name Exbucklandia for the Hamamelidaceous genus Bucklandia R. Br., non Pr. ex Sternb., while describing a new fossil species from the United States. He also transferred B. populnea to the new genus. Unfortunately I had overlooked this publication when proposing Symingtonia to replace Bucklandia R. Br. (Acta Bot. Neerl. 1: 443\xe2\x80\x94444. 1952). Exbucklandia will have to be accepted for it in future. The Indo-Chinese species B. tonkinensis Lecomte should be referred to as Exbucklandia tonkinensis (Lecomte) Steen. comb. nov. I have to thank Dr E. H. Walker for pointing my attention to R. W. Brown\xe2\x80\x99s paper.

Description: This charming and handy book printed on excellent paper, with its numerous clear pictures of well-known Malayan plants, reminds one in many ways of Merrill\xe2\x80\x99s \xe2\x80\x9cPlant Life of the Pacific World\xe2\x80\x9d (MacMillan 1946, New York), which has perhaps served Prof. Holttum as an example. Its size being only slightly smaller than Merrill\xe2\x80\x99s book and the area covered being very considerably smaller, its descriptions of plants are naturally more detailed; the more so as only a choice has been made, in which the special interests of the author \xe2\x80\x94 ferns, orchids, gingers \xe2\x80\x94 are evident though not predominant.\nThe plants described are not regionally arranged. The 17 chapters are rather headed by names of life-forms, striking organs, and special habitats. As is pointed out in the Preface, the book is \xe2\x80\x9cintended primarily for the Malayan resident who wishes to begin a study of Malayan plants\xe2\x80\x9d. In this purpose the book will doubtless prove to be a success: the reader is gradually taught quite a bit of botany of various fields, morphology, anatomy, ecology, hybridisation, etc. These are demonstrated at plants which are within easy reach of the ordinary layman for which it is destined. Short opening and concluding chapters deal with general features of tropical plants and with the Malayan forest. Since the author is a well-known expert and the Malayan flora as here described is a very good example of any flora between, say, Calcutta and Fiji, it may well be useful to residents of many other countries as well.

Description: The first result of this survey of the wide genera which have endemic species in New Caledonia is certainly to confirm the impression that there is indeed a noteworthy geographical association between Madagascar and that island, even if it is only a particular aspect of a more general relationship between Madagascar and Australasia as a whole.\nBut the survey gives prominence also to another point, namely the unexpectedly small part that tropical Africa plays in the distribution of the genera reviewed. It almost seems as if there is some factor of exclusion affecting that great region, and there is no indication of any corresponding degree of relation between tropical Africa and New Caledonia such as has been detected between the latter and Madagascar.

Description: Trees with leaves crowded at tip of thick branchlets; stipules subulate or narrowly deltoid, caducous; leaves, obovate or obovate-oblong, tertiary nerves ascending near the midrib, transverse near the margins of the leaf; flowers crowded at tips of branchlets, forming a pseudo-terminal, many-florous inflorescence; calyx with two whorls of two lobes each; corolla exsert, tube solid, pubescent without at apex, petals 8, imbricate; stamens 9\xe2\x80\x9440, inserted in one or two rows in the throat; style subulate, exsert, glabrous; ovary glabrous, 3\xe2\x80\x948-celled, cells 1-ovuled, ovules attached at the apex of the central axis; sometimes an indistinct annular disc present; fruit large, often edible, crowned by the persistent style; fruit usually 1-seeded; seed ovoid with large to very large scar and apical hilum; testa thick, crustaceous; albumen none or membranous, if present especially around the radicle; cotyledons fleshy; radicle inferior, not exsert \xe2\x80\x94 11 species distributed from the Moluccas to the Samoa and Tonga Islands.\nThe last revision of this genus was given by Lam in 1942. After a small but important publication of White (J. Arn. Arb. 31, 1, 1950, 104) and the investigation of some new collections it seemed appropriate to give a concise revision of this genus in preparation for the \xe2\x80\x9cFlora Malesiana\xe2\x80\x9d. Some new species are described and of some old ones more details are given. The publications of Lam are abbreviated as follows: 1925 = The Sapotaceae, etc. of the Dutch East Indies, Bull. Jard. Bot. Bzg, s\xc3\xa9r. 3, 7, 1925, 112. Lam 1927 = Further studies etc., Bull. Jard. Bot. Bzg, s\xc3\xa9r. 3, 8, 1927, 381. Lam 1932 = Sapotaceae, in Nova Guinea 14, 4, 1932, 554. Lam 1942 = A tentative list of wild Pacific Sap. etc., Blumea 5, I, 1942, 36.

Description: A study has been made of the Indo-Malaysian species of Cnestis. The mutual length ratio of sepals and petals, \xe2\x80\x94 brevi- and aequipetaly \xe2\x80\x94, is the main differentiating character for the species; there are no transitions. The areas of distribution overlap in the Malay Peninsula (fig. 1); brevipetalous types are known from the Malay Peninsula, Sumatra, Borneo and Celebes, aequipetalous types from Burma, Siam, Indo-China and the Andaman Islands, the Malay Peninsula and the Philippines. Fruits are of two different shapes: beaked in aequipetalae of the Andamans, Burma, Siam, and Indo-China, pear-shaped in remaining aequipetalae and in brevipetalae. Leaves tend to be longer and jugae more numerous in brevipetalae than in aequipetalae.\nOther characters do not have so clear a separating value, such as texture and indumentum of leaflets, indumentum of inflorescence, texture and indumentum of petals, length of stamens, type and length of pistils, length ratio of stamens and pistils. However, even on the strength of these characters there is some reason to distinguish both groups mentioned above. As to the indumentum of petals there is a remarkable cline in a decreasing sense from the Philippines to continental Asia, the Andamans and the Malay Peninsula and back to the east through the brevipetalae of Malay Peninsula, Sumatra, Borneo and Celebes.\nBrevi- and aequipetalae have been considered to represent two species, viz Cnestis platantha Griff. and Cnestis palala (Lour.) Merrill. The latter one has been divided into two subspecies, viz subsp. palala with beaked fruits and subsp. diffusa (Blanco) Andreas with pear-shaped fruits. For their area of distribution see fig. 1.\nIn many respects some plants of the Andamans, Burma, Siam, Indo-China (and the Malay Peninsula) are different from the remaining aequipetalae, but not in a uniform way as to the various characters. Although there are some arguments for a further taxonomic subdivision, we did not think it advisable to introduce such a division at present. Our classification differs from the division as given by Schellenberg (1938). This was caused by the material on one hand, being more heterogeneous than Schellenberg described it, and, on the other hand, by the fact that some of the diagnostic characters used by him, in our opinion were not fit for use as such. Therefore a revision of Schellenberg\xe2\x80\x99s system of the genus Cnestis seems desirable.

Description: In January 1949 Professor H. J. Lam, director of the Rijksherbarium, Leyden, on his way to the 7th Pacific Science Congress in New Zealand, spending some time in Fiji, was shown by Mr B. E. V. Parham, Department of Agriculture, Suva, Viti Levu, Fiji Islands, a slender tree, cultivated in the Agricultural Experimental Garden Naduruloulou. The tree was unidentified and of unknown origin. Some flowering material was collected and at our request Mr Parham was good enough to send some ripe fruits in liquid for an investigation I was entrusted with.\nAdditional material was studied from the herbaria at Brisbane, Kew, Leiden, Melbourne and Paris. It is my pleasant duty to tender my best thanks to the directors of these institutes for the loan of this valuable material, among which the type.

Description: With reference to and in continuation of our elaborate announcement in Blumea VI, nr. 2, 1950, p. 544\xe2\x80\x94545, it is a pleasure to report now the publication of Vol. I, entitled: Malaysian plant collectors and collections, being a cyclopaedia of botanical exploration in Malaysia and a guide to the concerned literature up to the year 1950 by Mrs. M. J. van Steenis\xe2\x80\x94Kruseman (CLII + 639 pp., 3 maps and about 220 illustrations).\nThe General Part (roman page numbers) comprises introductory paragraphs (aim of work, interesting data and hints on labeling, lists of illustrations and literature of use to collectors and investigators, terminology of altitudinal zones, and the use of vernacular names) as well as chapters on the technique of botanical exploration and collecting, on the phytogeographical delimitation and subdivision of Malaysia, on the collections made in the area concerned (arranged both chronologically and geographically, with 1 map), statistics of collections and desiderata for further exploration with 2 maps), sources consulted for the data mentioned (literature and herbaria), and samples of handwritings of 70 collectors and botanists.

Description: In Madro\xc3\xb1o (1936) Herre has lamented the disappearance of lichen species through the disastrous interference of man. Unavoidably, the advance of civilised modern life is linked with destruction of the vegetation. This applies all the more as the endangered area is more densely populated and it certainly applies most alarmingly to the lichen flora of the Netherlands. Here, every way-side tree felled is an irreparable loss to the epiphytic lichen communities, every acre of heath burnt or turned into arable land is a blow to our stock of terrestrial lichen species, whereas the use of dry fertilisers and the spraying of orchards are very effective in killing any lichen in the neighbourhood that otherwise might have survived. A comparison of the material preserved in the older collections with what can be found nowadays, clearly shows what has gone lost. It is sad to think that an ever increasing number of species are on their way to total extermination.\nHowever, from a thorough investigation of the epiphytic communities of cryptogams latterly started by Mr J. J. Barkman, it becomes apparent that at least to some extent the losses may be compensated by the discovery of species hitherto overlooked or not recognised. It is on such and other finds that I intend to report from time to time.

Description: Though the new names published in Thunberg\xe2\x80\x99s \xe2\x80\x9cFlorida\xe2\x80\x9d have been entered in the Index Kewensis, few botanists have tried to verify the status and synonymy of the new species proposed in this 2-thesis booklet. Thunberg\xe2\x80\x99s names were entered in Juel\xe2\x80\x99s \xe2\x80\x9cPlantae Thunbergianae\xe2\x80\x9d (1918, 412 pp.).\nThe diagnoses are generally too short and vague to allow a definite opinion. Only Schott, Mueller Arg., and F. E. Wimmer have examined material of resp. the Araceae, Euphorbiaceae, Campanulaceae.

Description: As early as 1939 I started a study of Papuan Nothofagus, and since 1948 I was entrusted with the elaboration of all the material my colleagues could lay hands on. This work was repeatedly interrupted on account of official duties. Pending the full account of the work in the Journal of the Arnold Arboretum I regret that it seems necessary to safeguard my conclusions as soon as possible.

Description: Xyris malmei sp. nov. \xe2\x80\x94 Folia ensiformia, 7\xe2\x80\x9430 cm longa, subfalcata, minute papillosa. Scapus 20\xe2\x80\x9445 cm longus, teres vel subteres, papillatus. Bracteae ovatae ad ellipticae, obtusae, emarginatae vel retusae; bracteae basales cum nervo uno completo et nervis 4 descendentibus incompletis. Sepala lateralia naviculata, cum carina glabra carinata. Petala obovata, 8\xe2\x80\x949 mm longa, ungui 7\xe2\x80\x948 mm longo. Stamina 3\xe2\x80\x944.5 mm longa, antherae basi obtuse, apice profunde incisae, thecarum apex acute bifidus. Staminodia penicillata. Ovarium obovoideum. Stylus trifidus, ramulis apice capitatis.\nTypus: Robinson & Kloss 5962, in K: Malay Peninsula, Kedah Peak, 850\xe2\x80\x94 1200 m, Dee. 1915.

Description: Koorders, Fl. v. Tjibodas 2 (1923) 32\xe2\x80\x9446; Hochreutiner in Candollea 2 (1924\xe2\x80\x941926) 336\xe2\x80\x94359; Ochse, Indische Groenten (1931) 719\xe2\x80\x94722; Backer, Onkruidfl. Java Suiker (1930) 203\xe2\x80\x94209; Aimshoff in Blumea 5 (1942\xe2\x80\x941945) 515\xe2\x80\x94517. Miss Dr G. J. Amshoff started the revision of the Javanese Urticaceae, but left the definitive preparation to me.\nUrtica dioica L. and U. urens L. have been erroneously recorded for Java (Miquel, Fl. Ind. bat. 1\xc2\xb2, 1859, 227; Koorders, Exk. Fl. Java 2, 1912, 126). To my knowledge no specimens were ever collected there nor elsewhere in the Malay Archipelago.

Description: In my paper on Parmeliaceae (in Blumea, vol. 6, 1947) some remarks have been made concerning the taxa below the rank of species (p. 3\xe2\x80\x944), one of them being the statement that I was to try to hold an intermediate course between those authors accepting multitudes of varieties and forms, and others abandoning them all. In the eyes of both I may have failed.\nIn the present paper I am going to alienate myself still farther from the former group of authors in reducing varieties to forms and doing away with many other forms. Although in a way this contradicts my inclination towards a meticulous classification in my former paper, it should be borne in mind that not all genera in lichenology can be treated alike. I still believe in varieties and forms \xe2\x80\x94 considering e.g. Parmelia physodes very good illustration \xe2\x80\x94 but on the other hand I am well aware now that in following Hillmann, whom I shall always gratefully remember for his kind help during the early days of my lichenological training, I have been decidedly all too punctilious.

Description: Gynostemma hederifolia (Decne) Cogn. in D.C., Monogr. Phan. 3: 916, 1881. (\xe2\x80\x9chederaefolia\xe2\x80\x9d). \xe2\x80\x94 Sicyos hederifolius Decaisne in Nouv. Ann. Mus. Hist. Nat. Paris 3: 450, 1834.\nKANGEAN Island (N. of Bali): Gua Peteng, 1 M alt.; Backer 26948 (BO), 15-III1919, \xe2\x99\x82, filaments connate up to the top, leaves far more densely puberulous than in the next specimen.

Description: Little attention has been paid till now to the algae, transported to the Netherlands coast on drifting objects. About a century ago T. D. Vrijdag Zijnen and G. Bisschop (near Scheveningen, \xc2\xb1 1845), and L. H. Buse (between Wijk aan Zee and Zandvoort, \xc2\xb1 1840\xe2\x80\x941847) were the first to pay attention to this subject. The material collected, especially that by the first two investigators, is mentioned in the Prodromus Fl. Bat. (1853). The book of Van Goor (1923) contains a chapter on these algae, in which, however, only few new observations occur. The author is much indebted to Dr Josephine Th. Koster for her kind help, as well as to Dr S. J. v. Ooststroom. The material, collected by Vrijdag Zijnen, Bisschop and Buse is almost completely present in the collections of the \xe2\x80\x98Rijksherbarium\xe2\x80\x99 and the \xe2\x80\x98Koninklijke Ncderlandse Botanische Vereniging\xe2\x80\x99, Leiden. The material, collected during the last few years has for the greater part been brought together by the present author, and furthermore especially by K. Swennen (Den Helder), J. Stock (Amsterdam), A. Mulder (Haarlem) and P. Leenhouts (Scheveningen). This material belongs to the collection of the Rijksherbarium, Leiden, but most of it is, for the time being, put under the charge of the \xe2\x80\x9cComit\xc3\xa9 ter Bestudering van de Nederlandse Mariene Flora en Fauna\xe2\x80\x9d (\xe2\x80\x9cCommittee on the Netherlands\xe2\x80\x99 Marine Flora and Fauna\xe2\x80\x9d) and temporarily preserved in \xe2\x80\x9cHet Filiaal\xe2\x80\x9d, Leiden.

Description: G. kingiana (Brace) Van den Assem, Blumea VII\xc2\xb2, 1953, 373.\nVar. kingiana, l. c. 373.

Description: Dialium hydnocarpoides, sp. nov. \xe2\x80\x94 Foliola (15)17\xe2\x80\x9419, elliptice oblonga, 4.5\xe2\x80\x946.5(8.5) cm longa, 2\xe2\x80\x942.5(3) cm lata, apice abrupte breviter acuminata. Sepala extus pubescentia, intus puberula. Stamina 2, raro 3. Ovarium in receptaculo plano, lato, strigoso excentrice insertum. Stylus glaber. Legumen fere globosum, leave, velutinum, c. 15 mm diam.\nTypus \xe2\x80\x94 Sumatra, Palembang, prope Lematang Ilir: FRI 185 T. 3 P. 541 (L).

Description: Combretum kostermansii Exell, sp. nov.\nFrutex scandens, ramulis primo fulvo-pilosis et tomentellis demum sparse pilosis, atro-rubris. Folia opposita breviter petiolata, petiolo 1\xe2\x80\x943 mm longo, piloso, lamina chartacea, ovata vel oblongo-ovata, basi cordata, apice acuminata, 2\xe2\x80\x947 X 1.8\xe2\x80\x943.6 cm, supra nitidula, costa media excepta pilosula fere glabra, subtus ad nervo adpresse pilosula, haud lepidota, costis lateralibus utrinsecus 3\xe2\x80\x946. Flores \xe2\x99\x82+ protogyni, 4-meri, sessiles, albi, in paniculas terminales et axillares, rhachide fulvopiloso, bracteis filiformibus 3\xe2\x80\x944 mm longis fulvo pilosis dispositi. Receptaculum inferius 1\xe2\x80\x941.5 mm longum, dense pilosum, superius cupuliforme, 1.5 X 2.5 mm, pilosulum. Calycis lobi ovato-acuminati, 1 X 0.9 mm. Petala 4, late ovata, apiculata, 2 X 1.5 mm, pilosa. Stamina 8, biseriata, filamentis 2.5 mm longis, glabris, primi inflexis, antheris 1 mm longis glabris. Discus inconspicuus. Stylus 4 mm longus, glaber. Ovuli 2.

Description: The Netherlands Antilles may be divided into: (1) The Cura\xc3\xa7ao Group (or Netherlands Leeward Islands): Cura\xc3\xa7ao, Aruba and Bonaire. (2) The St. Martin Group (or Netherlands Windward Islands): (Netherlands) St. Maarten, Saba and St. Eustatius. The latter islands are very small, forming together only 8.1 per cent of the total area of the Netherlands Antilles, and 2.2 per cent of its population.\nThe Cura\xc3\xa7ao Group often has a desert-like aspect with a \xe2\x80\x9ctropical dry-forest\xe2\x80\x9d vegetation. Therefore on these islands the mosquito pest is nothing like so bad as it usually is in the tropics. There are few permanent breeding places, except man-made receptacles in and around the houses to store rainwater or well-water in as the Government waterworks do not always produce sufficient and adequate water. The St. Martin Group has a higher rainfall and a more abundant vegetation.\nIn the preceding pages the morphological characteristics which are of taxonomic value have been described. Keys to the mosquitoes, their classification, their geographical distribution and their biology observed in the Netherlands Antilles have been given.\nMosquitoes may be spread by automobiles, ships and airplanes on the islands. Fortunately, all airplanes from foreign airports and St. Maarten are sprayed on Cura\xc3\xa7ao and Aruba. Except this measure little was done before 1951 to control mosquitoes, except in the areas occupied by the oil companies. An anti-A\xc3\xabdes aegypti campaign was initiated on Cura\xc3\xa7ao in October 1951 and on Aruba in March 1952 (residual DDT house spraying and larviciding).\nBecause of the paucity of mosquito records of the Netherlands Antilles a rather thorough survey was made on Cura\xc3\xa7ao from 1941- 1947, while the other islands were visited only for a short time.\nAt the moment 20 species are known from the Netherlands Antilles.\nAnopheles pseudopunctipennis pseudopunctipennis was found on Cura\xc3\xa7ao and rarely on Aruba, and An.albimanus once on St. Maarten, but never an indigenous case of malaria has been reported from the Netherlands Antilles. The larvae of An. pseudopunctipennis were found in earth-lined breeding places, but also frequently in manmade receptacles. Nearly all these breeding places contained clear, fresh or slightly brackish water with green algae; the majority were sunlit. Though the females of An.pseudopunctipennis attacked man, they were more attracted to animals.\nCulex quinquefasciatus was a common domestic pest mosquito on all of the islands. Though it often bred in earth-lined breeding places, it was found more frequently in man-made receptacles. The water was fresh or slightly brackish and usually polluted. Wuchereriasis bancrofti prevailed at a low rate on the Cura\xc3\xa7ao Group (4.2%, of which at least 2.7% was indigenous) and at a higher rate on the St. Martin Group (10.3% of which at least 5.1% was autochthonous). Elephantiasis was very rare.\nA\xc3\xabdes aegypti was the most common domestic pest mosquito on both groups of islands. It was usually caught in clear, fresh water in man-made receptacles in or around human dwellings. The females bit in the daytime and at night. Several epidemics of yellow fever occurred in the previous century; the last one was on Cura\xc3\xa7ao in 1901. The last sporadic case occurred on Cura\xc3\xa7ao in 1914. Dengue was very common in newcomers from non-endemic areas.\nHaemagogus anastasionis was collected on Cura\xc3\xa7ao and rarely on Aruba. The larvae were mainly found in tree holes after occasional rains. All the breeding places contained dark brown rainwater with a layer of humus. The bite of the female is painful. Fortunately it has not been incriminated as a vector of jungle yellow fever. Besides, there are no wild monkeys on the Netherlands Antilles.\nWyeomyia celaenocephala was found in various species of bromeliads on the Christoffelberg on Cura\xc3\xa7ao. The females will bite fiercely in the jungle.\nUranotaenia lowii was collected from a pond on Bonaire.\nA\xc3\xabdes taeniorhynchus was mainly caught in stagnant, sunlit beach pools with clear, dark brown, brackish water on Cura\xc3\xa7ao, and once in a well on Saba. The females are severe biters.\nA\xc3\xabdes busckii was found in a tree hole on St. Eustatius.\nPsorophora cyanescens was reported from Aruba only once.\nPsorophora confinnis bred in rock holes and other earth-lined breeding places, and rarely in man-made receptacles on the Cura\xc3\xa7ao Group. The majority of the breeding places were temporary and sunlit, and contained clear or turbid rainwater. The females are fierce biters. They entered houses.\nPsorophora pygmaea was collected from a ditch on St. Maarten.\nDeinocerites cancer was mainly found in crab holes on both groups of islands. The water of the breeding places was turbid and brackish. Adults lived in the crab holes. Females did not bite the author.\nCulex erraticus was caught in clear fresh water near the airport on Cura\xc3\xa7ao.\nCulex americanus was found in various bromeliads on the St. Martin Group.\nCulex bahamensis was collected from fresh or brackish water on the St. Martin Group.\nCulex habilitator adults and larvae were found in crab holes on St. Maarten.\nCulex maracayensis was caught in earth-lined breeding places and sometimes in concrete tanks and troughs on Cura\xc3\xa7ao. The water was usually clear, shaded and fresh or slightly brackish.\nCulex nigripalpus was collected near the airport on Cura\xc3\xa7ao from a temporary ground pool with rainwater.\nMegarhinus guadeloupensis was found once in a bromeliad on Saba.

Description: While engaged on working out the beautiful pycnogonid material dredged by Dr Th. Mortensen in shallow waters near the Virgin Islands, I thought it useful to compare this dredged material with material collected between the tide marks, or just below the low tide line. So I was very glad to meet Dr P. Wagenaar Hummelinck, who has made extensive collections of littoral marine animals during his various trips to the West Indies, and who kindly entrusted me with about 50 lots of pycnogonids which had already been sorted from his material.\nA definitive paper will be published as soon as his entire marine material has been searched for the presence of sea spiders.

Description: This paper presents the results of the examination of a fairly big collection of mollusca from the island of Mandul, north of Tarakan, East-Borneo. The material was collected by Dr. Van Holst Pellekaan while investigating the geology of Mandul in the service of the \xe2\x80\x9cBataafsche Petroleum Maatschappij\xe2\x80\x9d (Royal Dutch/Shell). It was sent to Prof. K. Martin of Leyden for closer examination, and afterwards was embodied into the collections of the Leyden Geological Museum.\nProf. Martin recorded the results of his preliminary examination, which excluded the bivalves, in a report to the \xe2\x80\x9cBataafsche\xe2\x80\x9d, dated 12th January 1917. He came to the conclusion that the fossils were of a Pliocene age.

Description: La stratification des roches cristallines (d\'\xc3\xa2ge ant\xc3\xa9st\xc3\xa9phanien) des massifs centraux des Alpes est en g\xc3\xa9n\xc3\xa9ral \xc3\xa0 peu pr\xc3\xa8s parall\xc3\xa8le \xc3\xa0 la schistosit\xc3\xa9. \xc3\x89galement les intrusions granitiques y sont plus ou moins concordantes.\nCependant les recherches sous la direction du Professeur E. Niggli de Leiden ont d\xc3\xa9montr\xc3\xa9 que le contact est du massif granitique des Sept-Laux (Massif de Belledonne s. 1.) est concordant seulement en grandes lignes avec la schistosit\xc3\xa9, tandis qu\'il est parfois nettement discordant en d\xc3\xa9tail (voir la publication dans un des num\xc3\xa9ros suivants de ce p\xc3\xa9riodique).

Description: Miopliocene marls from the island of Buton yield a large marine foraminiferal fauna and some calcareous algae. Three-hundred and thirthy-three species have been identified. Two genera, twenty-three species and four varieties are described as new.\nThe existence of mud-volcanoes in young neogene time is advocated.

Description: Le texte contient l\'explication de la carte, des profils et du tableau stratigraphique. La description lithologique fait mention d\'une dolomitisation du D\xc3\xa9vonien moyen, montant quelquefois plus haut, et de quelques poudingues dans le D\xc3\xa9vonien sup\xc3\xa9rieur. Un affleurement probablement du D\xc3\xa9vonien inf\xc3\xa9rieur dans un facies gr\xc3\xa9seux et fossilif\xc3\xa8re, est exceptionnel dans les Pyr\xc3\xa9n\xc3\xa9es. Dans la tectonique on a essay\xc3\xa9 de faire une \xc3\xa9valuation des influences alpines et hercyniennes s\xc3\xa9par\xc3\xa9ment. Puisque le m\xc3\xa9tamorphisme de contact des granites de Foix et de Lacourt ne monte pas plus haut que le Gothlandien, leur \xc3\xa2ge reste incertain, quoique des dykes et sills acides traversent le Carbonif\xc3\xa8re. La min\xc3\xa9ralisation due au granit\xc3\xa9 ne monte nul part plus haut que le D\xc3\xa9vonien.

Description: Un des plus grands ph\xc3\xa9nom\xc3\xa8nes structuraux des Pyr\xc3\xa9n\xc3\xa9es est sans doute la faille Nord-Pyr\xc3\xa9n\xc3\xa9enne qui longe la zone axiale depuis la M\xc3\xa9diterran\xc3\xa9e jusqu\'\xc3\xa0 la c\xc3\xb4te atlantique.\nElle est caract\xc3\xa9ris\xc3\xa9e par plusieurs particularit\xc3\xa9s exceptionelles, dont le m\xc3\xa9tamorphisme des terrains jurassiques et cr\xc3\xa9tac\xc3\xa9s inf., accompagn\xc3\xa9 d\'intrusions de roches basiques est le plus important.

Description: Identification of natural alkali felspars with X-ray powder photographs.\nX-ray powder analysis is becoming an important tool for the petrographer when identification problems can not be solved with the usual optical and chemical methods.\nIt is the aim of this paper to provide data to identify alkali felspars in groundmasses of extrusive rocks, perthites and other fine grained structures. Moreover the variation of the intensities and the position of spacings of the powder patterns of natural alkali felspars is compared with the variation in optical properties and chemical composition.\nTo this purpose alkali felspars of different localities, chemical composition, crystallization temperature and rate of cooling are investigated with optical methods, X-ray powder analysis and as far as possible, chemical analysis.\nThe optical examination of the alkali felspars was made with the four axes universal stage. The position of the poles of crystallographic elements and twinning axes was determined with respect to the axes of the indicatrix N\\u03b1, N\\u03b2, N\\u03b3. The co-ordinates are recorded according to Nikitin (1936). The quadrant in which each pole is situated is indicated by the sign + or \xe2\x80\x94.\nIn plate III the measurements on the potash-soda felspars are plotted in a projection normal to N\\u03b21. The interpretation normal orthoclase-Naorthoclase was made with the aid of the co-ordinates given by Nikitin (partly reproduced in table I) who did not give a chemical definition of these terms. The available chemical data in this investigation proved that thus defined normal orthoclase contained 〈 25 % Ab and Na-orthoclase 〉 25 % Ab in solid solution. Determination of refractive indices was used to distinguish anorthoclase from both \xe2\x80\x9clow temperature\xe2\x80\x9d albite and potashfelspar.\nThe alkali felspars investigated were grouped according to their natural paragenesis. Crystallization temperature, rate of cooling and stability within these groups are discussed. 1. Alkali felspar phenocrists from extrusive rocks.\nLarge sanidine phenoerists (d. 5,5 m.m.) from Lagno de Pollena, Vesuvius, show a zoned structure // (010), (fig. 3).\nIn sanidine of Siebengebirge wedged in between large homogeneous crystals (d. 8\xe2\x80\x9410 m.m.) appear small zoned sanidine crystals (d. 1\xe2\x80\x943 m.m.) which show polysynthetic twinning lamellae in many directions (fig. 2). Probably this is a product of later crystallization under stress.\nAnorthoclase of Puy de D\xc3\xb4me (fig. 7), Pantelleria and Mnt. Anakie, Australia (fig. 4) show an extremely fine albite twinning which seems to be typical for anorthoclase. Refractive indices (n\\u03b3=1,529) and X-ray powder pattern (fig. 18) are characteristic and different from those of \xe2\x80\x9clow temperature\xe2\x80\x9d albite.\nIn trachites of Colli Euganei, Italy, phenocrists were observed (fig. 5) with a core of \xe2\x80\x9chigh temperature\xe2\x80\x9d oligiclase (26 % An, 2V=\xe2\x80\x9484\xc2\xb0) passing in a rim of anorthoclase (2V=\xe2\x80\x9460\xc2\xb0). This proves the existence of a continuous series of solid solutions between h.t. oligoclase and anorthoclase. 2. Alkali felspars from plutonic rocks and dykes.\nExamples of cryptoperthites, orthoclase- and microcline microperthites and untwinned microcline are described. 3. Alkali felspars from pegmatites.\nDifferent structures of microcline perthites are described. In fig. 15 is shown how vein albite // (001), with an irregular surface regulates the position of adjacent microcline twinning lamellae. In this case the microcline twinning lamellae seem to be younger than the vein albite. On the other hand simultaneous crystallization as suggested by Spencer (1938, p. 107) seems not impossible. The most frequent occuring type of vein albite in microcline is reproduced in fig. 23, cutting the microcline lamellae under an angle of 60\xc2\xb0 with the (010) cleavage in (001). The vein albite is consequently younger than the microcline. Therefore Andersens (1928) suggestion that this vein albite is produced by infiltration of albite solutions in oriented shrinkage cracks may explain the constant orientation of the vein albite. Spencer\xe2\x80\x99s hypothesis of the cotectic origin of vein albite can only hold for isolated examples as mentioned in the description of fig. 15. The majority of vein albite in microcline is of secondary origin.\nExamples of patch perthite produced by replacement are shown in fig. 14 and fig. 24. As examples of \xe2\x80\x9chigh temperature\xe2\x80\x9d pegmatites a cryptoperthite from Larvik, Norway, and orthoclase from Itrongay, Madagascar, are described.\nA number of crystals of the well known monoclinic \xe2\x80\x9corthoclase\xe2\x80\x9d of Baveno produced X-ray powder patterns characteristics for microcline with additional albite reflections. Optical examination showed that these crystals are strongly altered to kalinite and invaded by secondary albite (see Baveno twin of fig. 8). Other crystals showed recrystallization of fine grained microcline and albite (fig. 9). With high magnification an initial microcline twinning is observed (fig. 10).\nIt seems probable that most crystal of Baveno \xe2\x80\x9corthoclase\xe2\x80\x9d on display in mineralogical musea, on optical examination will be found to show a pseudomorphosis of orthoclase by microcline. 4. The adularia-albite paragenesis.\nIn most of the examined adularia crystals from St. Gotthard, Bristenstock and Maderanerthal locally triclinic lamellae were observed which show extinction angles of 2\xc2\xb0\xe2\x80\x946\xc2\xb0 with the (010) cleavage in (001). These triclinic zones are nearly always situated round inclusions (fig. 21) and may be found in the core as well along the faces of the crystals. They are to be compared with the triclinic zones found in sanidine (fig. 2). Axial angles and extinction angles are different from microcline.\nChemical analysis in weight percents of some of the alkali felspars investigated are listed in table 2 and fig. 16. The Or-Ab-An components are expressed in molecular percents.\nSiO2 values are generally too low and Al2O3 and Fe2O3 values to high. For the samples no. 4, 48, 49, 33 and 23 this may be explained by the occurrence of alteration products.\nX-ray powder photographs were obtained with an iron target, Mn filter and a 9 c.m. diameter Unicam powder camera. The diameter of the diafragma slit was 0,3 m.m.. Tube current and voltage were 18 m.A. and 40 k.V. respectively. The accuracy of the measurement of spacings was 0,02 m.m. corresponding with 1,9\xe2\x80\x99 \\u03c6. Measurements were corrected by the admixture of 10 % Nall. Intensities were estimated visually.\nExamining the powder patterns of the alkali felspars, five groups could be distinguished, classified independently of chemical composition and optical properties.\nGroup A (plate I A and II A and B).\nA similar pattern was observed for sanidine, orthoclase of plutonic rocks, dykes and pegmatites and hydrothermal adularia. Samples investigated are listed in table 8. In table 3 intensities, \\u03c6Fe- and d-values are recorded for St. Gotthard adularia and Drachenfels sanidine. Characteristic are the two strongest reflections (202) and (002) (040).\nGroup B (plate I B).\nAll microclines and untwinned microclines give a similar pattern which diff\xc3\xa9ra from the group A pattern by showing a single strong (002) (040) reflection followed by three groups of each three reflections with the same intensity (p, q and r in fig. 17). Intensities, \\u03c6Fe- and d-values are recorded in table 4. Samples investigated are listed in table 9.\nGroup C (plate I C).\nThe powder pattern data of \xe2\x80\x9clow temperature\xe2\x80\x9d albite are recorded in table 5. Samples investigated are listed in table 10. Additional albite reflections of orthoclase- and microcline perthites are indicated respectively with AC and BC in table 8 and 9.\nGroup D (plate II D).\nIn table 6 are recorded the intensities, \\u03c6Fe and d-values of a typical anorthoclase. The investigated samples are listed in table 11.\nGroup E (plate II C).\nIn table 7 the powder pattern properties are recorded of a ciwptoperthite with a high An-content.\nThe facts recorded in table 8\xe2\x80\x9412 show complete agreement between the classification of alkali felspars with powder patterns and the classification on optical properties. It is not possible tot distinguish between sanidine and orthoclase with the aid of powder photographs. So the optical properties seem to be more sensitive to small changes in structure.\nThe powder patterns of all felspars have the strong reflection (002) (040) in common. The powder patterns of the alkali felspars with the exeption of \xe2\x80\x9clow temperature\xe2\x80\x9d albite differ from those of the plagioclases by the possession of an isolated strong reflection (043) (062), (d=1, 79\xe2\x80\x941, 78, s in fig. 17 and fig. 18).\nCharacteristic for sanidine, orthoclase and adularia (group A) with a composition up to 45 % Ab is the strong reflection pair (202) and (002) (040).\nThe microclines (group B) are characterized by a single strong (002) (040) reflection followed by three groups of each three reflections of the same moderate intensity (p, q and r in fig. 17).\nThe anorthoclase powder pattern which differs distinctly from the \xe2\x80\x9clow temperature\xe2\x80\x9d albite pattern is distinguished from the other alkali felspars by the presence of an isolated reflection of moderate intensity with d=3,15 (t in fig. 18).\nThe distance between the two strongest reflections (202) and (002) (040) of the powder patterns of sanidine, orthoclase from plutonic rocks, dykes, pegmatites and adularia proved to vary nearly linear with the Ab-content contained in solid solution. The distances were measured with the microscope with low magnification (X 19). In fig. 19 the variation of the distance between (202) and (002) (040) expressed in minutes (\\u03c6) is plotted against the Ab-content in molecular percents, calculated out of the chemical analyses available of homogeneous crystals of group A. The strong reflection of anorthoclase (106) seems to be doubled under the microscope. The corresponding distance does not fit in the diagram of fig. 19. A similar variation diagram for group A is plotted in fig. 20 in which the distances between the reflectons a and b (indicated in table 3) are used. The more time consuming absolute measurements of the position of certain spacings may also be used for the determination of the composition (see table 3\xe2\x80\x947 and fig. 17 and 18).\nThe Ab-component of orthoclase- and microcline perthites was easily observed in the diffraction patterns. Comparison with artificial mixtures of \xe2\x80\x9clow temperature\xe2\x80\x9d albite with orthoclase and microcline are shown in plate I, D, E, F, G. Excepting a cryptoperthite of Larvik, Norway, with an exceptional high An-content (group E) the albite component of the cryptoperthites (f.i. moonstone from Ceylon) could be easily detected. As in most cases only the strongest reflections of the albite component were present, is was not possible to make ure that \xe2\x80\x9chigh temperature\xe2\x80\x9d albite was present 1).\nAs contrasted with the cryptoperthites the investigated anorthoclases of Puy de D\xc3\xb4me, Pantelleria, Colli Euganei and Mnt. Anakie, Australia, proved to be optical and roentgenographical homogeneous. Although no natural or artificial \xe2\x80\x9chigh temperature\xe2\x80\x9d albite was available for investigation it seems probable that the powder pattern of anorthoclase (plate II D, table 6, fig. 18) must be similar to that of \xe2\x80\x9chigh temperature\xe2\x80\x9d albite.\nFelspars of rhomb porphyries, Oslo district, showed a powder pattern characteristic for oligoclase in agreement with the optical investigation of Oftedahl (1948).\nInvestigation of X-ray powder photographs of the plagioclases gave similar results as obtained by Claisse (1950). Powder patterns of anorthite from efflata of Monte Somma, Vesuvius (92 % An), anorthite of Pesmeda, Tyrol (94 % An) and anorthite of Kamitsuki, Miyake-Jima, Japan (98 % An), although very similar, showed differences in spacings and intensities which can not be explained by changes in composition. Differences in crystallization temperature and rate of cooling may be responsible for these structural differences.\nX-ray powder photographs of groundmasses of trachites, rhyolites, andesites, bostonites, pantellerites and helleflints showed the presence of alkali felspars, plagioclases and quartz (cristobalite, tridymite), see table 14. Comparison powder photographs of mixtures of quartz and felspar of known concentration permitted the estimation of the quartz content of the groundmasses.\nIn plate II E a powder photograph of charnockite is reproduced. With optical methods is was impossible to determine whether the mesoperthite present consisted of orthoclase- or microcline perthite.\nComparison with diffraction patterns of quartz (II F), a mixture of 80 % l.t. albite and 20 % quartz (II G) and a mixture of 80 % microcline and 20 % quartz proved the presence of quartz and microcline perthite in the charnockite.\nIn the last part of the paper the relation orthoclase-microcline is discussed and the existing opinions reviewed.\nThe hypothesis Mallard-Michel-L\xc3\xa9vy states that orthoclase consists out of submicroscopical twinned microcline units. The starting-point of this hypothesis is the supposed general occurence of intimately intergrown orthoclase and microcline. Now observations made by M\xc3\xa4kinen (1917), Baier (1930), Gysin (1928, 1938) and the present author tend to the conclusion that untwinned and partly twinned microcline are common; intergrowths of orthoclase and microcline however are limited to contactmetamorphic phenomena as described by Wimmenauer (1950). Triclinic lamellae in sanidine and adularia are not identical with microcline.\nThe influence of stress, advocated by Brauns (1891) as the cause of microcline formation is negligible, as is demonstrated by the common occurrence of free grown microcline crystals. The general occurrence of microcline in slightly metamorphosed rocks is due to the fact that these rocks attained equilibrium in the temperature region of 750\xc2\xb0\xe2\x80\x94500\xc2\xb0 C. (Spencer 1937, p. 481).\nOur optical investigation shows that there is a certain variation of the optical properties of microcline. A continuous change towards the optics of orthoclase was not observed. Considering these facts, together with the arguments put forward by Spencer (1938, p. 88), the submicroscopical twinning hypothesis seems improbable.\nAccording tot the hypothesis of Barth (1934), modified by Buerger (1948) microcline is formed by ordering of the Si and Al atoms with declining temperatures.\nThe difference in spacings and intensities found in the powder pattern of microcline indicates that the microcline structure shows a small distortion compared with the orthoclase structure.\nFinally the optical anomalies of adularia are discussed. The difference between the symmetrie relations of microcline and triclinic adularia is demonstrated in fig. 21 and 22.\nThe crystal structure of adularia seems to be similar to the orthoclase structure. Locally triclinic may originate round inclusions and disturbed areas during the crystallization. The structure of these triclinic lamellae is essentially different from the microcline structure originated by the complete ordering of the Si and Al atoms.\nContrary to the opinion of K\xc3\xb6hler (1948) it is evident that alkali felspars with an orthoelase structure crystallize at relatively low temperatures (450\xc2\xb0\xe2\x80\x94200\xc2\xb0 C.) which is also proved hy the occurence of authigenic felspar. Considering the polymorphism of the alkali felspars, exceptional conditions during the crystallozation must explain the formation of these \xe2\x80\x9clow temperature\xe2\x80\x9d forms.

Description: The deltas of the rivers Rhine, Meuse (Dutch: Maas), and Scheldt (Dutch: Schelde; French: Escaut) are connected so intimately that it is impossible to trace exact boundaries between them. Together they form a strip of Holocene deposits (clay, sand and peat), about 50 km wide, lying between the North Sea to the west and northwest and the Pleistocene region of the Netherlands to the east and southeast. The delta of the river Scheldt is the southern part of the joint deltas of the three rivers; it is nearly identical with the present province Zealand of the Netherlands.\nSecular fluctuations of the average level of the sea in relation to the land, both positive and negative, together with sedimentation and erosion, from the earliest times onward to the present day, continuously modified the local boundaries between land and water. The changing influx of salt water and the rate of drainage of the land always deeply influenced the vegetation and the whole character of the region. Moreover, since the Roman occupation in the beginning of our era, man had an ever increasing influence on the course of the river branches and on the water level in the rivers and ditches.

Description: Les Cop\xc3\xa9podes commensaux et parasites d\xe2\x80\x99Invert\xc3\xa9br\xc3\xa9s, quoique tr\xc3\xa8s communs dans toutes les mers, sont peu connus. En v\xc3\xa9rit\xc3\xa9, on en a d\xc3\xa9crit un nombre assez grand de genres et d\xe2\x80\x99esp\xc3\xa8ces, mais les descriptions sont trop souvent superficielles, voire m\xc3\xaame erronn\xc3\xa9es.\nUn de ces genres tr\xc3\xa8s peu connu est Tococheres, \xc3\xa9tabli par le Professeur Paul Pelseneer, 1929, pour un Cop\xc3\xa9pode trouv\xc3\xa9 sur les branchies de Loripes lacteus. Bivalve r\xc3\xa9colt\xc3\xa9 dans l\xe2\x80\x99Aber de Roscoff (Bretagne). La description de Pelseneer ne donne d\xe2\x80\x99informations que sur la forme generale de la femelle, sur les antennules et sur la cinqui\xc3\xa8me paire de pattes. On ne sait absolument rien sur l\xe2\x80\x99antenne, les pi\xc3\xa8ces buccales et les 4 paires ant\xc3\xa9rieures de pattes thoraciques.

Description: During the last few years several persons have been paying attention to the animals transported by floating objects (e.g. bunches of weeds and hydroids, corks, mines, floats, etc.). A careful examination of recent finds increased the list of species known of nearly all groups of marine animals, found washed ashore on the Dutch coast, and gave a good notion of the origin of passively transported floating objects on our shores.\nThe present authors, agreeing with IJzerman (1937), Kaas & Ten Broek (1939), Bloklander & Brouwer (1946\xe2\x80\x94\xe2\x80\x9947). Lucas (1950) and several others, in most cases look upon the Channel, the coast of Normandy and the South coast of England as their places of origin.

Description: The publication by ENGEL, GEERTS and VAN REGTEREN ALTENA (1940) on Alderia modesta (Loven, 1844) and Limapontia depressa Alder & Hancock, 1862, in the estuaries of southwestern Holland (provinces of Zuid-Holland and Zeeland) induced us to look for these animals on other Dutch mud-flats, viz. in the Waddenzee, where they had not been collected before.\nFirst we inspected the gullies between the mud flats, which contain more than 1 metre of water at high tide and, in addition, the Zostera nana-zone, which is dry at low tide and about under 50 cm of water at high tide. Lateron we searched for algae in the brackish inland waters, which will be mentioned below. In all these localities we did not find a single Alderia modesta or Limapontia depressa.

Description: As I have pointed out before, big game animals are very scarce in Museum collections. Many treatises are based on material from Zoological gardens, changed by captivity and often from unknown origin, from collections of frontlets, skulls and other trophies, bought haphazardly during expeditions which used all their time in thoroughly collecting the more interesting small animals. As a matter of fact, the rare species are better represented than the common ones, and the more a well-known species of game-animal is hunted, the fewer the specimens in the collections of the official Musea. The same is true for our knowledge of the biology of tropical big-game. Rare species, threatened by extinction, are studied with haste and often when it is too late to collect sufficient data. So, in preparing laws and regulations concerning the subject of hunting, one is always confronted with the fact that even the most necessary information is lacking.\nBarking-deer are game which is highly esteemed by hunters in our area, because they give good sport, the heads make nice trophies and perhaps also because the meat is excellent to eat. They are not scarce yet, no expensive hunting-parties are needed for an hour or two of shooting. In fact a man working on one of the large estates in Western Indonesia, may take his gun in spare-time and bring home a good buck before supper with a bit of luck.

Description: Ever since it became apparent that terrestrial animals ranging over large continental areas generally showed a certain degree of gradual geographic variation, attention has been focused on the colour variation of the Jay, Garrulus glandarius, in Europe. Surely the Jays belong to those species of palearctic land birds in which the formation of geographical differences must be considered to be exceptionally favoured: HARTERT (1903\xe2\x80\x941922; including HARTERT & STEINBACHER 1932) recognized as many as 10 European races of the Jay by name, whereas Kleiner (1935\xe2\x80\x9438) in his monographic treatment of the species numbered as many as 9 races in the same region. In several instances of the geographic variation of the Jay the differences are exceedingly striking, e.g. between the reddish brown Jays from Ireland and the dark grey ones from northern and central Europe. Still, the intergradations are so gradual and the individual variation is so unexpectedly large, that the application of subspecific names as a method of expressing geographical variation has proved to meet with serious difficulties. The resulting confusion of names for years has stressed geographical differences being of only minor importance and has obscured others meriting a closer attention.\nHowever, it was not at all for nomenclatorial purposes that this study was started, nor in order to propose a new arrangement of the geographic races of the Jay in Europa. That, in spite of this, these topics have been dealt with in one of the following chapters of this paper must be explained from the fact that the author failed to see a possibility to avoid them. The main purpose of this study was to investigate instances of \xe2\x80\x9cclinal variation\xe2\x80\x9d, meaning the presence and the origin of geographical character gradients. \xe2\x80\x9cCharacter gradients in the frequencies or in the expression of variable characters\xe2\x80\x9d (DOBZHANSKY 1947, p. 67) occurring in continuous geographical areas have seriously attracted the attention of students of population genetics and of micro-evolution. Hence it seemed worth while to select a suitable subject for a comparison of local individual variation with geographical variation and to study the origin of the clines. This is what the author has tried to do in the course of the present study on Garrulus glandarius.

Description: The problem of the retardation of the processes of growth and differentiation is certainly as important as the processes of growth and differentiation themselves. It is striking, therefore, that whereas the analysis of growth has been carried out for a considerable period of time already, the analysis of inhibition was only commenced a few decades ago. It has to be admitted that Wiesner (1894) succeeded in demonstrating the presence of a substance retarding germination in the slime of the mistletoe (Viscum album), but this remained a solitary observation for some time.\nAbout 1920 a series of important publications appeared which deal with inhibiting substances. Oppenheimer (1922) discovered a substance of this kind in the fruit pulp of ripe tomatoes, Reinhard (1933) found one in tomato juice, K\xc3\xb6ckemann (1934) some in other pulpy fruits such as apples, pears, quinces and tomatoes, Lehmann (1937) one in the exocarp of buckwheat, Ruge (1939) some in the fruits of Helianthus annuus and Avena sativa, Fr\xc3\xb6schel (1939, 1940) one in Beta, Stolk (1952, 1953a) some in the roots of Fuchsia hybrida and Pelargonium zonale and in the roots of Allium Cepa.

Description: Melongena Schumacher, 1817 (= Galeodes R\xc3\xb6ding) Thiele (1931, p. 320) gives the name Galeodes (Bolten) R\xc3\xb6ding, 1798, to this genus. This name, however, was already used by Olivier in the Encyclop\xc3\xa9dic m\xc3\xa9thodique, Insectes (1791, vol. 6, p. 578) for a genus of the Solifugidae. The author gave a detailed diagnosis and, moreover, described two species of the genus. Galeodes Olivier, 1791, obtains therefore priority in respect to Galeodes R\xc3\xb6ding, 1798, and this last name must thus be dropped as a hononym. Cassidula "Humphrey" (1797, p. 32), which is sometimes used, is not valid, as according to Opinion 51 the anonymous catalogue "Museum Calonnianum" "is not to be accepted as basis for any nomenclatorial work".\nThe next name to be considered for this genus is Melongena Schumacher, 1817. This author (1817, p. 212) gives a clear diagnosis of the genus and mentions as genotype M. fasciata [= M. melongena (L.)].\nAs in my previous catalogues I have, besides the species present in our collection, as far as possible, included here all the species of Melongena that are mentioned in literature. All the specimens from one collector in a certain locality, as far as they are kept dry, bear the same letter, whilst of the material preserved in liquor the number of the jar is given. In the list of species dealt with below, I have inserted these letters or numbers, followed by a number indicating how many specimens we possess from that locality.\nAfter the locality the name of the collector is mentioned; when the locality or the name of the collector is unknown I have placed a note of interrogation. 1. Sect. Melongena s.s.\nM. corona (Gmelin)

Description: Dr. E. Jacobson spent some months on the island of Simalur, and on some of the smaller islands in its immediate neighbourhood in the course of the year 1913. He made extensive zoological collections on these islands, whose fauna was very little known up till that time. Amongst his material was a series of shells belonging to the Pleurodontid genus Amphidromus.\nThis series has been entrusted to me by Dr. Van Regieren Altena, and I am grateful to him for the chance of seeing these very interesting shells, and for the help he has given me in dealing with them. I have too to thank Mr. G. L. Wilkins for the figures.\nSimalur is the most northerly of the long chain of large islands which lie along the West coast of Sumatra. The whole chain is roughly 1000 km in length from North to South. Its several islands are separated from Sumatra, and to some extent from each other by sea-depths of 500-1000 fathoms. Simalur itself is about 90 km in length; Pulau Babi or Saranbau is a smaller island lying S.E. of Simalur. Oelau Lekon (or Lekoeen) is a still smaller island near Pulau Babi. Dr. Van Regieren Altena tells me that Oelau is a local form of the Malay word Pulau.\nLoosjes (1953) has described Pseudonenia Jacob soni, a Clausiliid, collected by Dr. Jacobson on Simalur. Apart from this I can find no record of land mollusca from the island.\nOn the other hand three species of Amphidromus have been recorded from Nias Is. which lies about 100 km South of Simalur and is rather bigger. These species were described by Fulton (1907), and a full account of the land molluscan fauna of Nias was published by Van Benthem Jutting (1934-193S).

Description: In 1935 Lee Boone in Bulletin of the Vanderbilt Marine Museum vol. 6 (pp. 160-163, pls. 41, 42) described and figured a shrimp, which she thought to belong to a new genus and species of the Palaemonid subfamily Pontoniinae, and which she named Vanderbiltia rosamondae. Boone\'s figures and description show that the specimen cannot possibly be a Pontoniid shrimp, but it proves to be impossible from these data alone to place the species anywhere in the system. In my report on the Pontoniinae of the Siboga Expedition (Holthuis, 1952, p. 22), therefore, I listed Vanderbiltia rosamondae (misspelled rosamundae by me) under the "species described as Pontoniinae, but not belonging in this subfamily\'\', and remarked that the species shows some resemblance to the Atyidae and that it might be juvenile.\nThough according to the description and figure Vanderbiltia in some characters resembles the Atyidae, in others (e.g., the shape of the chelae) it differs so much from any of the members of that family that it hardly could be placed there. The identity of Vanderbiltia rosamondae Boone, which species had not been recorded since the original publication, therefore remained a mystery that only could be solved by examination of the type specimen itself.\nIn April 1953 I had the pleasure of visiting the Vanderbilt Museum in Centerport, Long Island, New York. Mr. Woodhull B. Young, curator of the Museum, whom I am profoundly thankful for giving so much of his valuable time to show my company and myself around in the Museum, and for extending many courtesies to us, was good enough to allow me to take the type specimen of Vanderbiltia rosamondae (or Vanderbiltia mirabilis, under which name it was exhibited in the Museum) with me to Washington,

Description: Though Schlegel (1866, p. 200) as well as Hartert (1898, p. 135) pointed out that Carpophaga paulina, described by Bonaparte (1850, p. 35) and now known as Ducula aenea paulina (Bp.), originating from the Sula Archipelago (East of the East Coast of Celebes) seemed not quite similar to birds from Celebes, lack of sufficient material refrained these authors from separating Sula birds. But this was done by Siebers (1929, p. 152/3) who separated them under the name Ducula aenea sulana, on account of their smaller wing measurements and the darker (more chestnut coloured) nuchal patch. The Sula birds should be also smaller than nuchalis from the Philippines and (doubtful) pulchella from Togian 2) which, according to Siebers, should belong to the same "Formenkreis" as paulina and sulana.\nSiebers compared 8 birds from Sula (1 \xe2\x99\x82, 5 \xe2\x99\x80 and 2 sex. inc.) in which the length of the wing varied from 208 to 216 mm with 5 specimens (3 \xe2\x99\x82 and 2 \xe2\x99\x80) originating from Celebes (Paloppo and Bone) having wings varying from 218 + x to 234 mm and with 7 skins (4 \xe2\x99\x82 and 3 \xe2\x99\x80) from Muna and Buton with wing measurements diverging from 232 to 248 mm.\nBesides the 20 birds studied by Siebers I could examine 18 more skins of these pigeons, viz., 3 from the Sula Islands, 2 from Pulau Peleng (island off Northeast Coast Celebes), 4 from Bumbulan (North Celebes), I from North Celebes (exact locality unknown), 1 from Kulawi (Central Celebes), 2 from Bone (South Celebes; Siebers\' statement that Bone is situated in North Celebes must be a slip of the pen), 2 from South Celebes (exact locality unknown), 1 from Mara (Mare?, South Celebes) and 2 from Muna (island off the Southeast Coast Celebes). When comparing these 38 skins (31 specimens from the Buitenzorg Museum and 7 from

Description: Among the fossil proboscidean remains collected by Mr. H. R. van Heekeren in the Tjabeng\xc3\xa8 area, Sopeng district, about 100 km Northeast of Macassar in Southwestern Celebes there are a number of very small teeth.\nThey can be referred to the species of Archidiskodon of which I originally described two specimens of M2 or M3, some molar fragments, the distal end of an ulna, and the proximal end of a tibia (Hooijer, 1949), to which could later be added a fine M3, and an M1 or M2, both completely preserved (Hooijer, 1953a).\nArchidiskodon celebensis Hooijer is the smallest species of Archidiskodon known at present. Its molars are only one-half as large in linear dimensions as those of Archidiskodon planifrons (Falconer et Cautley), and they agree with the latter in their ridge-plate formula, configuration of the enamel figures of the worn plates, long roots, and degree of hypsodonty.\nAs will be seen from what follows, the Celebes pygmy elephantine also agrees with A. planifrons in what is considered to be the most important distinguishing character of A. planifrons, viz., the presence of premolars.\nMilk molars have been less intensively studied than molars; there are three of them, in Archidiskodon as well as in the recent species Data on DM2-4 of Archidiskodon planifrons from the Upper Siwaliks of India, of A. meridionalis (Nesti) from the Villafranchian of Europe, and of A. exoptatus Dietrich from the Early Pleistocene of East Africa are given in Fal1) A preantepenultimate milk molar (DMI) occasionally develops in the African elephant (Morrison-Scott, 1939). coner and Cautley (1845-49), Falconer (1868), Adams (1877-81), Pohlig (1888-91), Weithofer (1890), Dietrich (1942), and Osborn (1942). These

Description: In literature only very scanty information is to be found about the viscera of the Boid genera Tropidophis and Trachyboa, and therefore I believed it worth while to publish some notes which I made during dissections of the following species and subspecies: Tropidophis melanurus (Schleg.), Tropidophis maculatus haetianus (Cope), Tropidophis pardalis pardalis (Gundl.) and Trachyboa gularis Ptrs. The notes are in no way exhaustive; the specimens have been preserved in alcohol for a long time, and therefore it was not possible to study all features in detail.\nAll but two genera of the Boidae have two well developed lungs. One of these two exceptions was mentioned already by Cope (1894, pp. 218, 220: Ungualia; 1900, p. 697), viz., the genus Ungalia (i.e., Tropidophis of present day nomenclature). In this genus only one lung is present, and besides1 a tracheal lung has developed. The second exception is the genus Trachyboa; the fact that in this genus too a tracheal lung and only one true lung have developed, seems to have escaped notice up till now. As will be shown below there are also other features in which Tropidophis and Trachyboa agree with one another, while they differ from the other Boidae.\nTropidophis melanurus (Schleg.) Specimens examined: 1 $, Cuba, leg. Ramon de la Sagra, Mus. Leiden reg. no. 1299. 1 # juv., Cuba, leg. Ramon de la Sagra, Mus. Leiden reg. no. 1298.\nBoth specimens were labelled "Ungalia maculata", but after due consideration I refer them to Tropidophis melanurus (Schleg.). Especially the identification of the male no. 1299 caused me some difficulties, and therefore I may give my reasons for this identification. This male has a quadrifurcate

Description: I. Grouping of European species of the genus Astata Latr.\nIt is not my intention to anticipate in this paper a subgeneric division of the genus Astata 1). For the purpose of such division, it would be necessary to investigate more non-European material than at present is at my disposal.\nBut at first view it seems to me that the European species may be divided into four distinct groups, which may be separated with the key given below.\nTwo of the proposed groups (the stigma-group and the tricolor-group) form part of the subgenus Dryudella Spinola, as this subgenus has generally been understood; nevertheless, the differences between these two groups, namely in the shape of the clypeus and, in the females, in the habitus, seem to justify separating them; although, investigation of allied non-European species might make it necessary to adapt or to modify the key to the groups.\nEventually, the possibility that non-European intermediate forms will make the separations untenable cannot be absolutely excluded. A decision about the taxonomic rank of the proposed groups, therefore, must be postponed.\nSpinola (1843, P- 135), erecting the genus or subgenus Dryudella ("une nouvelle coupe, qu\'on appellera genre ou sous-genre, selon les principes qu\'on aura adoptes dans la nomenclature binominale"), based the "nouvelle coupe" on the wing venation of "Dimorpha cincta Perris" and separated it from "Dimorpha" 1) "par la troisieme cubitale, lunulee comme dans les "Lyrops" 2) et par la premiere nervure recurrente, qui s\'anastomose avec la nervure transversale qui separe la premiere de la seconde cubitale". However, in these critical features, Spinola was incorrect in several respects. Even excluding stigma and its near allies from Dryudella (Spinola himself never

Description: In a paper on some birds from Sumatra in the Leiden Museum Dr. Junge (1948, pp. 314-15) lists two males of Limosa lapponica baueri Naum. taken by Mr. Van Heurn on the beach at Tandjong Tiram in the Deli district on 14 November 1921. In a short discussion on this record he refers to the fact that Vorderman (1890, p. 416) gives this species as probably occurring in Sumatra, and subsequently Robinson & Kloss (1923, p. 326) and Chasen (1935, p. 37) list it without query or comment. Dr. Junge adds that he failed to find the reference on which the later authors decided that the bird was definitely known from Sumatra. It is probable that no such reference exists and that Dr. Junge\'s paper constitutes the first authentic published record of the occurrence there of the Eastern Bartailed Godwit. The point at issue is a general one which has puzzled other workers in this field, and it would seem to be of interest to outline the situation briefly.\nRobinson & Kloss published two lists of the birds of Sumatra, the first in 1918, containing 527 birds, and the second in 1923, giving 574 birds. In a note to their first list the authors (1918, p. 284) make the following comment on their treatment of the "Charadrii formes" (= Suborder Charadrii), "In this group Vorderman records with certainty only 14 species that are found on the mud-flats of the Strait of Malacca with one or two exceptions".\nIt is clear that by mud-flats of the Strait of Malacca they mean the flats on the eastern (Malay Peninsula) side of the strait. They disallow 3 of the birds given by Vorderman, but make their own total up to 30. At that time they had apparently no reliable Sumatran records for the great majority of the 19 species which they thus added to the Sumatran list. The same procedure was followed in compiling the second list, published in 1923,

Description: Records of cave-dwelling Lepidoptera are scarce in comparison with those in other orders of Insects, e.g., Coleoptera, of which even a whole subfamily (Silphidae, Bathysciinae) is in a most remarkable way adapted to this peculiar habitat. In the group of the so-called Microlepidoptera we could find examples of some eight species only, belonging to different families.\nApparently none of them is a true cave-dweller, i. e., a permanent resident of caves and really adapted to life in total darkness.\nCrypsithyris spelaea Meyrick, 1908 (Tinaeidae) only has been regarded as an exception. This species has been described from a large cave in Moulmein, Burma, and originally was reported as "being practically bleached or colourless", but with normally developed eyes and wings (Meyrick, 1908, p. 399). Later on better material has been collected at the same locality, and this time the moth appeared to be not quite colourless (Meyrick, 1916, pp. 602-603). It remains uncertain, therefore, whether there is question of any adaptation to cave-life and whether this species can be regarded as an "obligate cavernicole,, insect, the more so as larvae of closely allied species of this genus have been found living in the open, in portable cases on lichens covering rocks.\nFurthermore we could find reference to three species of the genus Tinaea: T. antricola Meyr., 1924, and T. pyrosoma Meyr., 1924, both from Siju Caves, Assam, and T. palaechrysis Meyr., 1929, from Batu Caves, Selangor (Malaya). Of the latter was said that it "belongs to the typically unicolorous yellow group, but has probably acquired fuscous colouring as an adaptation to cave life; it may therefore be a true cave-dweller, possibly restricted to these particular caves" (Meyrick, 1929, p. 375). Afterwards, however, Dam-

Description: In seiner Behandlung der Gattung Archon Hb. im Tierreich \xe2\x80\x9eLepidoptera pars I" kommt Bryk am Schluss seiner Betrachtungen zu der Feststellung, dass sich die geographischen \xe2\x80\x9eFormen" (subspecies?) in drei Gruppen zusammenfassen lassen. Unbestreitbar sind davon der \xe2\x80\x9ebellargus-Kreis" und der Rassenkreis, der die verschiedenen subspecies aus Pontus und Armenien beheimatet. Unklar ist die dritte Gruppe, zu der Bryk A. apollinus Herbst und subsp. thracica Buresch vereinigt.\nDie Diagnosen, die Bryk f\xc3\xbcr die verschiedenen Rassen gibt, zwingen mich, da ich sein tiefes Wissen von allem und sein Feingef\xc3\xbchl f\xc3\xbcr alles, was mit Parnassxus zu tun hat, kenne, zu der Annahme, dass ihm ein zu beschr\xc3\xa4nktes oder unzuverl\xc3\xa4ssiges Material bei seiner Arbeit zu Verf\xc3\xbcgung gestanden hat. Ich weiss aus eigener Erfahrung, das gerade von Archon ungez\xc3\xa4hlte Exemplare mit falschen Fundortetiquetten im Umlauf sind, oder solche, die den Vermerk e.l. missen. Das letztere ist insofern von Bedeutung, als mir eine grosse Anzahl e.l. Archon \xe2\x80\x94 teilweise aus eigener Zucht \xe2\x80\x94 vorliegen, die die Berechtigung der Aufstellung geographischer Rassen geradezu l\xc3\xbcgenzustrafen scheinen. Das Zudhtmaterial zeigt die ganze Variabilit\xc3\xa4tsbreite der Art und erinnert beispielsweise bei syrischer Herkunft kaum noch an das typische Aussehen von subsp. bellargus Staud. Zucht von Parnassiern ergibt fast stets Tiere, die vom Typus der betreffenden Rasse abweichen, aber sie doch nicht so vollst\xc3\xa4ndig verleugnen, wie es bei der grossen Serie Material, Herkunft Beyrouth, in meiner Sammlung der Fall ist.\nWas ist aber der typische apollinus? Bryk f\xc3\xbchrt als Fundort f\xc3\xbcr den Typus \xe2\x80\x9eUmgebung von Aleppo (Insel Kurlak)" auf, gibt aber als Verbreitungsgebiet gleichzeitig \xe2\x80\x9eKleinasien, Mesopotamien" an. Der Begriff \xe2\x80\x9eKlein-

Description: In a previous paper (1952, p. 190) I reported upon a specimen from the Lucie River, Surinam, doubtlessly belonging to Boulenger\'s genus Brachychalcinus, but had to abstain from giving a definite specific identification on account of the lack of comparative material, the insufficiency of previous literature, and the obviously juvenile state of the single specimen.\nA possibility to look once more into this matter, and to amend my previous statement, was brought about by the existence of eight specimens from the same river system, and probably belonging to the same species, in the collections of the Chicago Natural History Museum, and the offer to have these sent to me as a loan. For this courtesy, and for the loan of a single juvenile specimen of Brachychadcinus retrospina Boulenger, I am indebted to Dr. R. F. Inger, Assistant Curator of Fishes of the Chicago Natural History Museum.\nThe genus Brachychalcinus Boulenger (1892, p. 11) belongs to the subfamily Stethaprioninae, a subfamily allied to the Tetragonopterinae but differing by the possession of a procumbent predorsal spine. Within this subfamily, however, Brachychalcinus differs from the other, and better known genera, by the shape of this procumbent spine, described by Eigenmann & Myers (1929, p. 508) as "trigger- or hammer-shaped, its free portion forming a longer anterior and shorter posterior branch, both of which are sharply pointed". It is triangular in lateral view, with the longest side about continuous with the dorsal outline, its two further sides concave, and is attached with the lower angle. A similar spine is found just before the origin of the anal fin.\nOf this very rare South American genus, only two species hitherto have

Description: Two large specimens of a hitherto unknown species of neotropical catfish have recently been found dead and washed ashore beneath the dike along the Westerscheldt near Biezelinge, Zeeland, at a mutual distance of approximately 300 meters. Both were in excellent condition and have been presented to the Rijksmuseum van Natuurlijke Historie at Leiden by Mr.\nB. J. J. R. Walrecht.\nA superficial examination already disclosed the fact that the two specimens belong to the (sub)genus Selenaspis, a well known group of catfishes inhabiting the salt and brackish shores and estuaries of the northern part of the South American continent. Some of the species are known to spawn in fresh water. The present specimens must have been transported by ship.\nWhether they have been thrown overboard dead or alive remains uncertain though the first possibility seems more plausible. The damaged and fringed condition of the fins indicates a period of drifting along the shore, while the length of this period is limited by the still rather fresh condition, especially of the larger and first collected specimen. On the other hand, putrefaction seems to be slow in this group of fishes.\nOn his request, Mr. Walrecht received the information that no recent shipment of South American aquarium fishes had arrived at the aquarium of the Antwerp Zoological Garden.\nAn investigation of the stomachs of the two specimens gave the following results. In the larger specimen, no remains of food were found; in the second specimen, the stomach contained a considerable quantity of remains, viz., a part of a rib, possibly from a pig, measuring 1.8 by 5 cm; several pieces of cartilage; numerous split peas; several small remains of plants

Description: The sinus rhomboidalis sacralis or sinus lumbosacralis as it is named by Ariens Kappers (1920) is an interesting anatomical part of the lumbosacral region of the avian spinal medulla. It is found in birds only and neither in reptiles nor in mammals.\nFig. 1 shows the lumbosacral part of the spinal medulla of Phoenicopterus Pig. 1. Spinal medulla of Phoenicopterus, dorsal view, with sinus lumbosacralis and corpus gelatinosum. From Imhof (1905). seen from the dorsal surface and Fig. 2 represents a diagrammatic transverse section through the lumbosacral part. These figures show some peculiarities that are found in birds only. All vertebrates with hind limbs have a lumbosacral enlargement of the spinal medulla, but in birds this enlargement has become more pronounced through the presence of the lumbosacral sinus. At the dorsal surface of the medulla there is an elongated cleft, which we may call the sinus, and this cleft penetrates rather deep, deeper than the central canal. The cleft is filled up by a plug of peculiar gelatinous tissue, which protrudes in a marked degree above the surface of the medulla. This tissue is named by Terni (1924) the corpus glycogenicus because the cells contain a great mass of glycogen. Perhaps it is better to use the name corpus gelatinosum, as this name pretends nothing, and glycogen is of common occurrence in tumors and in many other tissues. Ariens Kappers (1924) has shown that this tissue is of a very complicated origin, it is partly glious, partly pial and partly arachnoidal, it contains blood vessels and it is composed of large vacuolized cells. It is remarkable that this gelatinous tissue, when transferred to 70 % alcohol collapses in a few minutes. Imhof (1905) has studied the embryonic development of the lumbosacral sinus