ALBERT

Description: In Madroño (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. However, 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: Of this series of preparations to the definite publication of the Burseraceae in “Flora Malesiana”, the present part is giving an additional note on VI. Garuga and dealing with the genera VII. Triomma, VIII. Dacryodes and IX. Santiria (and a new combination in Protium). The present paper gives only additions to and alterations of Lam’s monograph (H. J. Lam, Bull. Jard. Bot. Buitenz., Sér. 3, 12, 1932, 281— 561); descriptions, synonyms, litterature, specimens cited, ecological and other notes are only mentioned insofar as they are not given by Lam.

Description: A study has been made of the Indo-Malaysian species of Cnestis. The mutual length ratio of sepals and petals, — brevi- and aequipetaly —, 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. Other 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. Brevi- 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. In 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’s system of the genus Cnestis seems desirable.

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. A definitive paper will be published as soon as his entire marine material has been searched for the presence of sea spiders.

Description: En Zélande, province des Pays-Bas, l’on trouve différentes stations où croissent des algues marines. Ce sont: 1. Les digues, 2. Les canaux d’eau de mer, 3. Les parcs à huîtres, 4. Les slikkes et les schorres. La Zélande comprend une bande continentale et deux séries d’îles. Comparé aux autres provinces des Pays-Bas, le climat est assez tempéré. La température moyenne à Flessingue (Vlissingen) est de 3°C en janvier, le mois le plus froid, et de 18°C durant les mois les plus chauds, juillet et août. La température moyenne de l’eau de mer en surface est de 1— 3°C en janvier et de 19°C en juillet et août.

Description: Premna brongersmai, nov. spec. — Frutex? Ramuli teretes conspicue subdistanter lenticellati 0.3—0.5 cm crassi, internodia in specimine 7—11 cm longa. Folia coriacea subrigida, decussatim opposita glaberrima petiolata, ovata vel oblongo-ovata vel subovata vel oblongo-lanceolata, basi plus minusve late rotundata, marginibus integra, apice abrupte vel subabrupte peracute acuminata, latiora 8.5—11 X 4.7—5.7 cm, angustiora (in eodem specimine, ut apparet) 12—14.5 X 4—4.5 cm ; nervi haud prominentes, costa media subtus prominente excepta; nervi secundarii graciles utrimque 5—7, curvati, margines versus diminuti haud confluentes, tertiarii pertenues subdistanter transversi, reticulatione minutissima areolata; petioli e basi incrassata 1— 1.7 cm longi tenues. Inflorescentiae paniculatae terminales, partiales inferiores ex axillis foliorum parvorum, superiores ex axillis bractearum subulatarum 0.3—0.1 cm longarum ortae, totae 12—17 cm longae, 17—29 cm latae, partiales medianae longiores, e pedunculo gracili 10—14 cm longae, pseudodichotomice late divaricatae, ramificationes ultimae dichasiales minute pubescentes. Flores parvi tetrameri subsessiles, alabastris pyriformibus, glabris; calyx glaber cupularis subbilabiatus, c. 0.25 cm altus, labio inferiore acute integro vel leviter acuto-bidentato, superiore 2 lobis majoribus acutis suffulto, calyx intus praecipue dimidio superiore multis glandulis in sicco opacis munitus; corolla in regione staminum insertionis tantum intus pilosa, cetera glabra, 0.4—0.45 cm alta, tubo subcylindrico 0.3—0.35 cm longo, limbo aestivatione cochleata subbilabiato, labio inferiore trilobo (lobo medio in alabastro ceteros tegente, 0.15 cm longo, rotundato, lateralibus 0.1 cm longis, subtruncatis), superiore integro 0.1 cm longo subtruncato, in alabastro omnino tecto; regio pilosa sub labio superiore paulo infirmior; stamina alternipetala in regione pilosa aequa altitudine inserta, subdidynamia, filamentis sub labio superiore paulo brevioribus in alabastro sigmoideo-sinuatis 0.2 cm longis, sub labio inferiore 0.25 cm longis, omnibus vittatis apice abrupte contractis filiformibus; antherae 0.05 X 0.1 cm, subreniformes, thecae poris ovatis dehiscentes; ovarium globosum glabrum 0.15 cm altum 4-loculatum, loculis uniovulatis; ovula longa apotropa medio affixa; stylus filiformis 0.25 cm longus, stigma bilobum, lobis acutis piano mediano patentibus. Fructus ignoti. Shrub? Branchlets (all?) apparently long and drooping, 0.3—0.5 cm in diam.. Leaves decussate, entirely glabrous, ovate to ovate-oblong, base more or less broadly rounded, apex more or less abruptly and very acutely acuminate, margins entire, 8.5—14.5 X 4—5.7 cm, nerves not prominent except midrib below, secondary ones 5—7, curved, reticulation minutely areolate between the almost inconspicuous transverse tertiary ones; petioles 1—1.7 cm long, incrassate at base. Inflorescences widely paniculate, terminal, 12—17 cm long, 17—29 cm broad, the lower partial panicles in the axils of ever smaller leaves, the upper ones in those of subulate bracts; ultimate ramifications dichasial, minutely pubescent. Flowers subsessile, 4-merous, glabrous but for a hair ring inside at the insertion of the filaments. Calyx cupular, more or less bilabiate, 0.25 cm high, lower lip entire or shallowly acutely bidentate, upper one with two larger acute teeth, inside with dispersed dark glands: corolla tube suibcylindrical 0.3—0.35 cm long, aestivation cochleate, slightly 2-lipped, lower lip 3-lobed, midlobe rounded and 0.15 cm long, lateral ones subtruncate and 0.1 cm long; upper lip entire, 0.1 cm long, subtruncate. Stamens 4, subdidynamous, those below upper lip with slightly shorter filaments; filaments ribbon-shaped, 0.2 and 0.25 cm long respectively, subabruptly narrowed below the anther and ending into a very thin apex; anthers kidney-shaped, 0.05 X 0.1 cm, with two ovate pores; ovary globose, glabrous, 0.15 cm high, 4-celled, cells uniovulate, ovules long, apotropous, attached in the middle of the cell; style filiform, 0.25 cm long, stigma with two acute lobes spreading medianly. Fruits unknown.

Description: Casearia amplectens Sleum. sp. nov. — Arbuscula 1.5 m alta; ramulornm apicibus dense breviter flavido-pilosis, partibus vetustioribus cito glabratis corticeque cinerascenti obtectis. Folia elliptico-oblonga vel oblonga, apicem versus breviter (1—2 cm) subcaudato-acuminata, apice ipso paullo falcato obtusa, basi late cuneata fere rotundata, inferiora usque ad 2 mm longe petiolata, superiora subsessilia, membranacea, arcte pellucido-punctata et -lineata, petiolo, costa nervisque subtus brevissime pilosulis exceptis glabra, in sicco brunnescentia, utrinque opaca, regulariter crenato-serrata (dentibus obtusiusculis glandula terminatis 1 mm altis et c. 3—6 mm distantibus), 9—15 cm longa, 4—4.5 cm lata, costa utrinque elevata, nervis lateralibus utroque latere 6—8 curvato-ascendentibus praeter marginem excurrentibus supra subimpressis, subtus elevatis, venis supra obscuris, subtus parum conspicuis. Stipulae reniformes fere amplectentes, membranaceae, 4—6 mm altae, 6—8 mm latae, persistentes. Flores pro axilla. 1—2 fere sessiles, in statu nondum plane evoluto tantum visi; bracteae paucae membranaceae glabrae 1—2 mm longae. Calyx tubulosus, carnosulus, c. 3 mm longus, extus fulvo-sericeus, intus glaber, lobis oblongis c. 1 mm longis. Stamina 10, alte ad faucem inserta; filamenta glabra, medio dilatata, alternatim 0.6 et 0.3 mm longa. Staminodia rudimentaria parum pilosa. Ovarium columnare, glabrum, c. 3 mm longum, 1 mm crassum. Fructus carnosus, ruber, 1.5—2 cm longus, 1 cm diam., trivalvis, basi calycis lobis accrescentibus 4 mm longis et 1.5 mm latis fultus, 2 mm longe pedunculatus. NEW GUINEA. W. New Guinea, 4 km SW of Bernhard Camp, Idenburg Riv., rain-forest undergrowth, 850 m: L. J. Brass 13470 (A; L, typus), fl. fr. March 1939.

Description: The X-ray powder method for determining minerals has been applied to the important rock-forming mineral group of the pyroxenes in this thesis. The purpose of the investigation was to seek the relationship between the variations of the intensities and positions of the reflections in the powder diagram and the variations in optical properties and chemical composition. For that purpose a number of pyroxenes from different localities were investigated optically, chemically and röntgenographically. The orthopyroxenes. — The optical examination of the orthopyroxenes indicates, that the variation of the optical properties is related to the chemical composition (see Table 1). A difference between plutonic and volcanic orthopyroxenes lies in the size of the optic axial angle 2 V; this appears to be smaller with volcanic orthopyroxenes between En80 and En15 than with plutonic orthopyroxenes (see fig. 5). Further a lamellar structure can be observed in the plutonic orthopyroxenes (see figs. 2 and 3) while the volcanics do not have these lamellae but often show zoning (see fig. 1). It is seen from chemical investigation of the orthopyroxenes that both the plutonic and volcanic orthopyroxenes show about the same variation in Al- and Ca-atomic proportions (see Table 3). It is quite possible that a part of the Ca content of the plutonic orthopyroxenes is present in exsolved diopside lamellae according to the hypothesis of Hess and Philips (1938). The orthopyroxenes can be distinguished from the clinopyroxenes by X-ray powder diagrams on the ground of their characteristic reflection pattern. These powder diagrams are made by means of a camera with a diameter of 9 centimeters and FeK\u03b11 radiation (\u03bb = 1.93597 Å). All powder diagrams of the orthopyroxenes are classed as one group (Group A, see fig. 6). The variation in the relative distance between the reflections 10 31 and 0 6 0 appears to be connected with the chemical composition. These distances are measured very accurately in millimeters by means of a Cambridge Universal Measuring Machine and plotted against the chemical composition in fig. 8. Through the influence of Al and Ca, the Mg content cannot be determined unequivocally from this diagram. Therefore also X-ray powder photographs are made of a mixture of 70 % orthopyroxene and 30 % quartz (see fig. 9). The relative distance between quartz reflection 2 1 3 1 and pyroxene reflection 0 6 0 in millimeters and the distance between quartz reflection (2 0 2 3) (3 0 3 1) and pyroxene reflection 11 3 1 in millimeters depend on the chemical composition which can be seen in figs. 10 and 11, respectively. In fig. 10 two curves are shown, one for orthopyroxenes with an atomic proportion of Al of about 0.010 and one for those with an atomic proportion of Al of about 0.050 in BVI position. In fig. 11 two curves can be seen which are related to orthopyroxenes with an atomic proportion of Ca of about 0.020 and those with an atomic proportion of Ca of about 0.060. One may determine the chemical composition of an orthopyroxene from these three diagrams (figs. 8, 10 and 11). For that purpose one should measure three relative distances. In each diagram one can find two values for the Mg content. From these, a total of six values, three will lie close to each other; the average of these three values indicates the Mg content. With this Mg content one can determine the Al and Ca contents in the diagrams. This röntgenographic method meets with difficulties when there do not occur certain proportions of Al and Ca in the orthopyroxene. Then there may be present two groups of three Mg's which lie close together (see Table 9). In such cases of doubt one must use the optical method to determine the Mg content. By substitution of Fe for Mg, Nz changes strongly, the unit cell dimensions do not, however, and neither do the relative distances. The Al and Ca contents then may be determined by the röntgenographic method. By substitution of Al and Ca for Mg, the unit cell dimensions change strongly and with them the relative distances between the reflections, which are very sensitive. The variation in the relative distance between the reflections mentioned has been explained by means of a crystal model of enstatite (see figs. 12 and 13). This variation results from the substitution of Fe, Al and Ca for Mg and of Al for Si. The substitution of Fe for Mg increases the unit cell dimensions only slightly so that the shape of the unit cell also changes little. The substitution of Ca for Mg has a great influence on the a- and the c dimension, which both become much greater. The substitution of Al for Mg and of Al for Si strongly decreases the b dimension. These changes in the unit cell occur because all substituting ions have a different ionic radius from Mg and moreover because in the structure of enstatite two kinds of Mg ions occur with altogether different positions and which are linked with the tetrahedra in very different ways. Since the relative distance in millimeters between certain reflections depends on the camera and radiation used, in Tables 7a, 7b and 7c these distances are stated for a few types of camera and radiation. In addition the differences between the lattice spacings of these reflections are given in Ångström units. The clinopyroxenes. — In this thesis the optical investigation on clinopyroxenes consists of a description of the specimens, both macroscopieally and microscopically and a determination of 2 V and Z \u039b c. For a few clinopyroxenes the values of Nz and Nx have also been determined. The described clinopyroxenes are subdivided in a number of groups; this classification is based upon the chemical composition (see p. 224). It turned out that the optical properties of the röntgenographically investigated clinopyroxenes do not differ much from the data mentioned in the literature about this group of minerals (see fig. 20 and Table 10). The chemical investigation is restricted to the analysis of a few clinopyroxenes; the results are stated in Table 11. On the basis of difference in position and intensity of certain reflections in the X-ray powder diagrams a classification in four groups has been established for the clinopyroxenes. Group B 1 (figs. 21 and 23) The group includes, hedenbergite, diopside, augite and diallage. Group B 2 (figs. 21 and 23) Pigeonite belongs to this group. Group B 3 (figs. 21 and 22) This group includes, aegirite and jadeite. Group B 4 (figs. 21 and 22) Spodumene belongs to this group. No sharp limits can be drawn between these groups and transitions may exist between some of these groups, as between groups B 1 and B 2 and also between groups B 1 and B 3. Through lack of clinoenstatite and ferrosilite samples we could not check whether any more groups may be distinguished. Of each of these groups the principal features are discussed on p. 245. Each group has its own characteristic reflection pattern; the similarity between these patterns, however, is great enough to conclude that all the investigated clinopyroxenes have a similar structure. The grouping of the X-ray powder diagrams agrees in the main with the classification of the pyroxenes according to the chemical composition. The chemical composition of the different clinopyroxenes of the groups B 1 and B 2 may be determined by a combined optical and röntgenographic investigation. This combination is necessary because the substitution of Fe for Mg has practically no influence on the dimensions of the unit cell, but it does have on the refractive indices. On the other hand the substitution of Ca for Mg strongly influences the shape of the unit cell. For the different clinopyroxenes of groups B1 and B 2 the variation of the relative distance in millimeters between the reflections 2 2 0 and 2 2 1, the reflections 2 2 1 and 3 1 0 and the reflections 1 3 1 and 2 2 1 is plotted against the chemical composition in figs. 25 and 26. From these diagrams one may determine the chemical composition by measuring the relative distances mentioned, on the X-ray powder diagrams. In figs. 27, 28 and 29 the relation between the chemical composition and the difference between the lattice spacings of the reflections in question in Å can be seen. Further Tables 16a, 16b and 16c indicate the distances between these reflections for a few types of camera and radiation. The X-ray powder diagrams of the alkali pyroxenes can be distinguished from those of the other pyroxenes, while they also show great mutual differences. It may be noted, however, that transitions between these pyroxenes always are possible. The powder diagram of spodumene has its own character, so that this pyroxene can be distinguished very simply from the other pyroxenes by the röntgenographic method. The X-ray investigation on clinopyroxenes is not yet completed, because much can still be done, for instance in the jadeite-diopside-aegirite field.

Description: During the study of the Xyridaceae of the Malaysian area it was desirable to study those of Australia and Continental Asia as well. The Malaysian species now have, in the meantime, been published (Flora Malesiana, ser. 1, 4, 1953, 366—376). To the new taxa described in Blumea 7, 1953, 307—308 the Latin diagnoses of the following new species and a new section may here be added: 1. Xyris linifolia van Royen, nov. spec. — Fig. 1. Herba mediocris, ad 40 cm alta. Folia subulata, ad 25 cm longa, c. 1 cm diam., subfalcata, acuta, sparse papillata; vaginae 6—8 cm longae, basi 3—6 mm latae; ligula brevis acuta c. 1 mm longa. Scapus 20—40 cm, c. 1 mm diam., teretiusculus, 2- vel pluricostatus, minute papillatus. Capitula ovoidea ad globosa, pauciflora, ad 7 X 6 mm, bracteae basales suborbiculares, 4.5—5.5 X 3.5—4 mm, obtusae, enerves, in parte superiori minute papillatae, papillis arcum triangularem formantibus, medianae obovatae, 6—6.5 X 4.5—5 mm, nervosae, nervis nervo mediano et uno nervo completo in costae utroque latere orto ad bracteae apicem laxe reticulato compositis, in parte mediana superiori minute papillatae, papillis aream suborbicularem formantibus. Flores masculini ignoti, florum femineorum sepala lateralia angusta, 5.5—6.5 X c. 1.5 mm, acutiuscula, emarginata, ecristata, alata, alis sat latis, sepalum medianum cucullatum, 4.5—5 X c. 2 mm, binerve. Petala nondum evoluta limbo orbiculari 4 mm longo et lato munita, margine serrata, unguiculo c. 2 mm. Stamina c. 3 mm, antherae c. 2 mm, apice profunde emarginatae, basi apiceque obtusae thecis emarginatis. Staminodia 2.5—3 mm, penicillata bifida? Ovarium incomplete cognitum, stylus 4.5—5 mm (vel longior?), trifidus, ramificationibus c. 2.5 mm, apice capitatis. Capsula ignota. Typus: Smiles s. n. in K. Distr.: Siam — in open grassland near base of Mt Kau. This species differs from all Malaysian species except X. borneensis in the terete leaves and the three complete nerves of the bracts. Though the leaves of X. borneensis are also terete, the bracts are provided with numerous complete nerves. Moreover, the lateral sepals in X. borneensis are ciliate, those of X. linifolia smooth and entire. In its anthers the present species resembles X. ridleyi, X. pauciflora, X. borneensis, X. capensis, X. complanata etc., the anthers being deeply incised at the top and the thecae emarginate. 2. Xyris nigromucronata van Royen, nov. spec. — Fig. 2. Herba annua parva, ad 6 cm alta. Folia linearia, 1—2.5 cm X c. 1 mm, mucronata, apice nigra et pilis robustis paucis hispida, anguste bi-alata, alis tenuiter et sparse papillatis, in parte basali elliptica in sectione transversa, apice incrassata et triangularia in sectione transversa, vaginae 3— 6 cm longae, apice pilis multis albis munitae, margine membranacea, marginibus pedunculi basin includentibus, pedunculo ligula biloba pilis destituta praedito. Scapus ad 6 cm longus, subangularis, valde obscure alatus, alis 1 vel 2, proxime infra capitulum elatus ubi 3- vel 4-alatus. Capitula oblongo-ellipsoidea, c. 7 X 5 mm, bracteae omnes cristatae, basales ovatae, c. 6.5 X 3 mm, sat brunneo-nigrae, mucronatae, mucrone ad 2.5 mm longa, cristata, nigra, crista pallide flava in parte apicali tantum tenuiter et sparse papillata, medianae subcirculares ad panduriformes, 4—5 X 2—5 mm, margine sat brunneo-nigrae, uninerves, nervo completo laevi, in parte basali membranaceae. Sepala lateralia naviculata, fere ad apicem connata, c. 5 X 1 mm, membranacea ecristata. Petala 6, alba, 6—7 mm longa, unguiculata, ungui 4—5 mm, arcte cohaerentia et quasi tubulosa, limbo elliptico-oblongo, obtuso, c. 2 X 0.8 mm. Stamina 6, c. 1.2 mm, antheris ovoideis, c. 0.6 mm, truncatis, emarginatis thecae basi obtusae; filamenta subulata, c. 0.6 mm. Staminodia desunt. Ovarium subovoideum ad ellipsoideum, c. 2 X 1 mm, trilobum, in parte basali 3-, in parte superiori 1-loculare, stigmatibus 3 terminatum. Capsula ovario similis, sed ad 3 X 1.5 mm metiens; semina sparse papillatae. Typus: Pritzel 635 a in L. Distr.: Australia — in scrub between Moore and Murchinson river. This specimen was found mixed with Stylidium bulbiferum Benth. var. septentrionale Mild braed in Pritzel 635. Therefore it is separated from that species under 635 a. This highly characteristic species differs from all other species of Xyris by the fimbriate top of the sheath, the united lateral sepals (also found in the Brasilian X. obtusiuscula Nilsson), the 6 united petals, the 6 stamens (also once found by the author in X. bancana Miquel), the more or less campylotropous ovules, the entire style, and the papillate curved seeds. Moreover, the flowers seem to be white but owing to the dried material it can not be stated for certain whether this is the proper colour. These details warrant the establishment of a separate section in Xyris, Australoxyris with the following Latin diagnosis: Xyris Linnaeus, sect. Australoxyris van Royen, nov. sect. Folia apice in sectione transversa triangularia, vaginae exteriores apice ciliatae, flores capitati; sepala lateralia maxime connata; petala 6, connata; stamina 6; stylus simplex; ovarium in parte basali 3-loculare, in parte superiori 1-loculare; ovula plus minusve campylotropa; semina papillata. Typus: Xyris nigromucronata van Royen.

Description: The present paper deals with the results of my investigations on the Tenebrionidae of the Leeward Group and the xerophilous regions of Venezuela and Colombia. I am much indebted to Dr P. Wagenaar Hummelinck for giving me the opportunity to study the material he collected during his trips to this area. Some other specimens used were collected by the present writer himself. Material for comparison has been obtained through the courtesy of several people, particularly the Director of the British Museum (N.H.), Mr H. Kulzer (Frey collection, Munich), and Prof. E. Tortonese (Museum of Zoology, Turin University), to all of whom I am deeply obliged. In particular I also wish to thank Prof. E. Gridelli, Director of the Natural History Museum, Trieste, to whom I am greatly indebted for his constant help and advice in my work, and to Prof. R. Malaroda, of the Institute of Geology, Padua University, for the useful criticism about my geological considerations. Not the last, I would express my gratitude to Dr E. MacC.Callan of the I.C.T.A. (Trinidad, B.W.I.) for the communication of material of that Institute. — The photographs were made by Dr P. Wagenaar Hummelinck, with the expert assistance of Mr H. van Kooten, at the Zoological Laboratory of the State University, Utrecht. The material has been deposited with the Zoological Museum of Amsterdam and the State Museum at Leyde. The material indicated as “Marcuzzi leg.” is included in author’s private collection, excepting some specimens which have been given to the Biological Department of the Caracas University, Venezuela.