ALBERT

Description: De hier besproken soorten zijn alle nieuw voor de Nederlandse fauna in zoverre, dat zij niet vermeld staan in de Catalogus Aranearum van VAN HASSELT. De collectie van deze araneoloog bevindt zich in het Rijksmuseum voor Natuurlijke Historie te Leiden en wordt daar momenteel gerevideerd, waarna een nieuwe naamlijst van Nederlandse spinnen zal worden samengesteld. In deze bijdrage wordt geen poging gedaan de twijfelachtige synoniemie van de Catalogus op te helderen, hetgeen zeker nog menige nieuwe soort voor ons land zal opleveren. Zij is slechts een tussentijds resultaat van het bewerken van de eigen collectie en van materiaal, dat mij van verschillende zijden ter bewerking werd toevertrouwd.\nDe gebruikte systematische indeling en de soortnamen zijn in hoofdzaak die uit de Katalog der Araneae Bd. I van ROEWER, waarbij echter enkele correcties op grond van nieuwere onderzoekingen werden aangebracht. Ook ben ik er toe overgegaan de namen van CLERCK te gebruiken.

Description: Weinig onderzoekingen hebben in zo wijde kring bekendheid verworven als die van onze landgenoot JAN SWAMMERDAM, die in zijn ,Ephemeri vita\xe2\x80\x99 (1675) en later in de ,Bybel der Natuur of Historie der insekten\xe2\x80\x99 (1737) de ontwikkelingsgeschiedenis beschreef van het beroemd geworden Oever-aas, Palingenia longicauda (Oliv.), de grootste palaearctische Ephemeride.\nDit allermerkwaardigst insect, dat \xe2\x80\x94 het zij terloops opgemerkt \xe2\x80\x94 reeds in 1634 door de Amsterdamse medicus AUGERIUS CLUTIUS was beschreven en afgebeeld \xc2\xb9), moet destijds in ons land alom de aandacht hebben getrokken wegens zijn massaal optreden gedurende een aantal warme dagen omstreeks het midden van de maand Juni. In Nederland echter is dit grote haft vermoedelijk reeds tegen het eind van de vorige eeuw uitgestorven. Thans leeft het nog in het stroomgebied der grote rivieren van Midden- en Oost-Europa (Oder, Weichsel en Wolga).

Description: In 1853 BLEEKER (I, p. 489 and 490) described two species, both from the bay of Batavia, as Julis (Halichoeres) cyanopleura and Julis (Halichoeres) pyrrhogrammatoides. He pointed out that these two species are closely related, the first to Julis poecilopterus SCHL., the second to Julis pyrrhogramma SCHL., both from Japan. Lastnamed species differ from the javanese species, besides by slightly different colourmarkings, by having 14 rays in the dorsal and the anal, against 11 rays in both fins of the javanese species. BLEEKER says that but for the difference in the number of dorsal and anal rays, which is considerable, at least for this genus, he would be temped to consider the javanese species as climatic variations (\xe2\x80\x9cklimaatvarieteiten\xe2\x80\x9d) of the japanese ones. He also draws attention to the great resemblance of these four species inter se, as they are all characterised by having 4 canines anteriorly in each jaw, and the outer pair in the upper jaw greatly curved backwards.\nWhen at a later date (2, p. 100) he found that the pharyngealia inferiora of H. cyanopleura and H. pyrrhogrammatoides differ from those of the other members of the genus Halichoeres by being concave posteriorly, he created a new genus Leptojulis with L. cyanopleura as the type. It is curious that in the discussion of this new genus in the Atlas Ichthyologique (3, p. 128) BLEEKER says: \xe2\x80\x9cJe ne connais du genre Leptojulis que les deux esp\xc3\xa8ces de mon cabinet, qui toutes les deux habitent la mer de Batavia\xe2\x80\x9d, and that no mention is made of the two japanese species, which formerly he considered to be so very closely related to them. We can guess why he did so, for some years later (4, p. 251) he gave an elaborate description of Julis poecilopterus and pyrrhogramma. The inferior pharyngeals are described as being not concave behind and agreeing in all respects with those of other species of Halichoeres, in which genus he now places the two species. Again, no mention is made of his species of Leptojulis, but the japanese species are now compared with Halichoeres bicolor and hyrtli, which have the same disposition of bands on the body, but differ in the number of canines and in the number of dorsal and anal rays.

Description: Lower-Villafranchian landmammals lived in the South of the Netherlands when the coastline of the North Sea retired in northern direction during the Plio-Pleistocene transition period. In the province of Zealand their black remains have been fished out of the waters of the Scheldt in the depth of which littoral Poederlian deposits (Amstelian deposits are missing there in Zealand) occur and are eroded by the currents. Also borings in the provinces of Limburg and Guelderland have yielded black fossils of this fauna of which the following species could be stated in the Netherlands: Eucladoceros falconeri (Dawk.), Odobenus huxleyi (Lank.), Alachtherium spec., Anancus arvernensis (Croiz. et Job.), Archidiskodon planifrons (Falc. & Caut.), Gazella schreuderae Hooijer and Mustela erminea L. This Lower-Villafranchian fauna occurs also in the Red Crag of East-Anglia, in Pi\xc3\xa9mont (Villafranca) and in Auvergne (Perrier, etc.).\nThis fauna lived in the south of the Netherlands in the forests and along the coast of the North Sea which then was a deep quiet bay covering a strip of East-Anglia, te larger portion of the Netherlands and a small portion of Belgium along the Belgian-Dutch frontier from the North Sea coast to the east in the direction of the Meuse near Venlo. South of this coast-line a broad communication between England and the continent caused the identity of their mammals in that period.

Description: It is for me a pleasure to contribute the following descriptions of chosen rarities to the Jubilary Volume in honour of the highly esteemed Prof. Dr. L. F. DE BEAUFORT and Prof. Dr. J. E. W. IHLE, of the University of Amsterdam.\nI wish to express my gratitude to Dr. J. WILCKE, Wageningen, and to Mr. W. F. BREURKEN, Amsterdam, for the execution of the drawings.

Description: The most recent comprehensive treatment of this Indo-Pacific genus \xc2\xb9) is that of TESCH (1918, p. 78-82). Here seven species are recognised with the reservation that M. eydouxi H. Milne Edwards and M. thukuhar (Owen) are possibly not distinct.\nIn 1936 (TWEEDIE 1936, p. 49) I questioned the validity of the character used to separate M. latifrons (White) and M. maculatus H. M.-E., the relation of carapace length and breadth, and placed maculatus in the synonymy of latifrons.

Description: 1. The term cline is proposed as an auxiliary taxonomic term, to denote graded spatial variation within a population. 2. This is in no way intended to replace the current methods of taxonomic specification by named areal groups. It may, however, supplement them usefully (a) by stressing continuity as against discontinuity, (b) by effecting synthesis in relating the characters of separate groups to general trends, (c) by obviating the need for assigning names to groups which are only slightly distinct. 3. Clines may be of two rather distinct types: a) compound or inter-group clines, connecting the means of characters of distinct groups (subspecies of a polytypic species, species of an Artenkreis). (b) internal clines, within a whole interbreeding group or any section of it. 4. Clines may concern size, colour, pattern, physiological resistance, the ratio between two or more distinct varieties, etc. 5. Some clines are adaptively correlated, either directly or indirectly, with corresponding environmental gradients or with other environmental factors such as colour of background. Others appear to be correlated with migration from a centre of distribution, still others with the production and subsequent migration of a mutant with positive selective value. Another type not adaptively correlated with environment is that of intermediacy between two distinct subsubspecific types across an interbreeding zone. 6. This last type of cline may be called a genocline. Other main types are geoclines, over large geographical areas, and ecoclines through a range of ecological habitats. 7. Some clines are related to development, in that the greater development of a character is related to greater intensity of rate-genes which determine it. 8. Quantitative figures for a few size geoclines in birds give changes varying from 0.5\xc2\xb0 to 2\xc2\xb0 N. lat. per 1 % change in size of part affected. 9. The principle of harmoniously stabilized gene-complexes, deduced by R. A. FISHER and others and empirically established by TIMOFEEFF-RESSOVSKY, will account for the extension of the range of particular genecombinations beyond the areas for which they were initially selected, and the restriction of intermediates to narrow zones between the ranges of the favoured stabilized combinations. 10. Owing to this principle, the existence of sufficient environmental diversity between different regions of a population\xe2\x80\x99s range will establish partial biological discontinuities, the population being broken up into relatively uniform subspecies covering larger areas and separated by interbreeding zones which are kept narrow by selection. 11. Even in the event of subsequent range-change, the intergrading zones will remain narrow. 12. The production of partial discontinuities will be facilitated by the existence (a) of regions of relatively rapid environmental change, (b) of regions of relatively low population density (partial isolation). 13. The tendency to produce a regular internal cline will thus be overridden, and replaced by a stepped cline. It is theoretically probable that the subspecific groups in such cases will show internal clines of slight slope provided that environmental conditions differ sufficiently across the subspecific range. 14. Geographical and physiological (ecological) isolation will also tend to introduce discontinuities into regular clines. The resultant discontinuous intergroup cline will tend to be steeper than the original continuous internal cline, while the internal clines within the various isolated groups will tend to be less steep.

Description: If you ask the layman: \xe2\x80\x9cWhat is a museum?\xe2\x80\x9d, he will answer. \xe2\x80\x9cA museum is a display of objects, that have an aesthetic value or scientific interest; the scope of a museum is to improve the taste of the visitor, is to give him, by visual means, aesthetic or intellectual enjoyment, to satisfy his curiosity, to show him the true and real things (a classic sculpture, an Indian weapon or a deepsea fish) instead of a documentary film, a radio report, or the descriptions and pictures in his books and magazines.\xe2\x80\x9d If an architect is in charge of designing a museum, he will see to it that the wallcases and the free-standing objects receive the right light and that the public and the conditioned air can circulate freely. He will design an entrance hall, an exhibition gallery, a director\xe2\x80\x99s room, and, perhaps, in the basement or on the top-floor a store-room for articles not on display \xc2\xb9).

Description: Toen ik als praeparator aan de Musea van het Genootschap werd aangesteld en mijn intrede deed in den mooien Artistuin met zijn hoog opgaand geboomte, had ik, als niet-Amsterdammer, nooit gedacht in dien tuin, gelegen in het centrum eener groote stad, zooveel vogelsoorten in wilden staat te kunnen waarnemen. Het bleek mij al spoedig, dat niet alleen in de voli\xc3\xa8res van de Diergaarde op ornithologisch gebied veel te beleven viel, maar dat ook wat daarbuiten in den vrijen staat voor een scherp toeziend oog op te merken was, niet verwaarloosd moest worden. Van dien tijd af ben ik dan ook begonnen notities te maken van alle waarnemingen, die in den loop der jaren gemaakt konden worden.\nIn totaal heb ik van 75 soorten aanteekening gemaakt.