ALBERT

Description: A sponge collection dredged by Dr. P. WAGENAAR HUMMELINCK in the vicinity of Barbados (West Indies) contained a Cinachyralike specimen bearing large and conspicuous acanthoxea. This find induced the present author to re-examine all specimens with similar spiculation reported so far. A review of the literature revealed that a total of three such specimens has been described in two different genera, all as separate species, viz. Acanthotetilla hemisphaerica Burton, 1959, Acanthocinachyra enigmatica Levi, 1964, and Acanthocinachyra seychellensis Thomas, 1973. Both genera are reported to differ in the presence (genus Acanthocinachyra) or absence (genus Acanthotetilla) of sigmaspire microscleres. In view of the close similarity of the two genera it seemed wise to compare all the specimens.\nMiss S. M. STONE (British Museum (Natural History), London) kindly consented to the loan of the holotype of Acanthotetilla hemisphaerica; Dr. P. L. G. BENOIT (KOninklijk Museum voor Midden Afrika, Tervuren, Belgium) and Dr. C. L\xc3\x89VI (Mus\xc3\xa9um National d\xe2\x80\x99Histoire Naturelle, Paris) readily sent the specimens of Acanthocinachyra seychellensis and A. enigmatica, respectively. Dr. P. WAGENAAR HUMMELINCK (Zo\xc3\xb6logisch Laboratorium, State University of Utrecht) is kindly thanked for his donation of the West Indian collection. Scanning Electron Microscope illustrations were made by Drs. S. WEINBERG, the other photographic illustrations by Mr. L. A. VAN DER LAAN (both ZMA), which aid is gratefully acknowledged.

Description: A large number of samples of Salpidae, Doliolidae and Pyrosomatidae, collected by the U. S. Ocean Acre Project, are studied. A new record for the Bermuda area of Doliopsis rubescens (Vogt, 1817) is given. Dominant species are Iasis zonaria (Pallas, 1766), Salpa fusiformis Cuvier, 1804, and Salpa aspera Chamisso, 1819. Seasonal peak occurrences are observed for several species. The seasonal and vertical variation of the number of muscle fibres of aggregate Salpa fusiformis and aggregate Salpa aspera is studied and discussed.

Description: Four remarkable dome-shaped, apparently juvenile colonies, belonging to the genus Pyrostremma Garstang, 1929, are described from the Bermuda area. Comparison with juvenile colonies of P.agassizi (Ritter & Byxbee, 1905), and with larger colonies, fragments and loose zooids of P.agassizi and P.spinosum (Herdman, 1888), has rendered it likely, that these juvenile colonies belong to P.spinosum. The species of Pyrostremma are discussed.

Description: The genera Cyclosalpa de Blainville, 1827 and Helicosalpa Todaro, 1902 are revised on the basis of material from all three oceans. Two new species, Cyclosalpa foxtoni and Cyclosalpa ihlei are described, and four taxa, formerly described as varieties or subspecies, are raised to specific rank. The existence of morphological groups of species within the genus Cyclosalpa is discussed.

Description: The existence of clinal variation in some morphological characters of Atlantic Salpa fusiformis Cuvier, 1804, is reported. The number of muscle fibres of both aggregate and solitary individuals is subjected to a decrease from higher to lower latitudes. Size and reproduction also seem to vary according to the latitude. The results and their bearing on infraspecific salp taxonomy are provisionally discussed.

Description: The age composition of a sample of a Stoat population from the Netherlands was studied. Various relative age criteria were tested on their validity in separating age groups. The study of the layered cemental deposits contributed the most important part to the final conclusions. By using also the data on the sexual cycle of the Stoat, a theoretically expected age pyramid was calculated, which was compared with the actually found age composition.

Description: The occurrence of the skull parasite Skrjabingylus nasicola (Leuckart, 1842) in Stoats and Weasels from the Netherlands has been studied extensively. A redescription is given of certain morphological characters of the parasite, which includes the discovery of hitherto unknown peribuccal papillae. The genus Skrjabingylus is discussed. The extent of infection and the damage caused by the parasite in Stoats and Weasels has been assessed by studying collections of preserved skulls. Detailed comparisons are made between the infection percentages in both species of mustelids in different areas of the Netherlands and in different European countries. Also the relation between infection and age and sex has been studied. In the discussion an attempt is made to explain at least some of the observed differences in extent of infection in the studied material.

Description: This paper represents the first part of a list of Coelenterate type specimens incorporated in the collections of the Zoological Museum. The present 46 pelagic Coelenterate types are listed with their original names accompanied by a non-critical and incomplete synonymy.

Description: The present paper, the first one of a series on West Indian Sponges incorporated in the collections of the Zoological Museum of Amsterdam, deals with the Keratosa. A total of 33 species is described and fully illustrated. Part of the material consists of the Duchassaing & Michelotti-collection housed in Amsterdam; of all the Keratosa-types of this collection a photographic illustration and an extensive redescription is given. Most of the type specimens are designated as (para-)lectotypes. Two new species are described, viz. Ircinia hummelincki from deeper water off Barbados, and Pleraplysilla stocki from mangrove forests in Puerto Rico. Five \xe2\x80\x9cforgotten\xe2\x80\x9d species are revived, viz. ? Coscinoderma musicalis (Duch. & Mich., 1864), Fasciospongia cerebriformis (Duch. & Mich., 1864), Hyrtios proteus Duch. & Mich., 1864, Hyrtios caracasensis (Carter, 1882) and Spongia solitaria Hyatt, 1877. Application of the priority rules of zoological nomenclature has led to the renaming of five species, viz. Spongia pertusa Hyatt, 1877 (for S. anclotea De Laubenfels & Storr, 1958), Hyattella intestinalis (Lamarck, 1814) (for Aulena columbia (De Laubenfels, 1936)), Oligoceras violacea (Duch. & Mich., 1864) (for O. hemorrhages De Laubenfels, 1936), Verongula rigida (Esper, 1794) (for V. ardis sensu Wiedenmayer, 1977) and Igernella notabilis (Duch. & Mich., 1864 (for I. (Darwinella) joyeuxi (Topsent, 1889)). New records for the West Indies are Ircinia dendroides (Schmidt, 1862) and Chelonaplysilla erecta Tsurnamal, 1967. The suborders, families, genera and species of Keratosa occurring in the West Indies are discussed; a proposal is made to give suborder status to the family Aplysinidae (= Verongiidae sensu Bergquist & Hartman, 1969). The zoogeography of West Indian Keratosa is preliminarily analyzed and some ecological remarks are made.

Description: The Salp genera Traustedtia Metcalf, 1918, Weelia Yount, 1954 and Brooksia Metcalf, 1918 are revised, resulting in the conclusion that Traustedtia is a monotypical genus, and that Brooksia on the other hand, contains two taxa, one of which is newly described under the name B. berneri. Weelia shows a confusing variation, which must await further study. The variation in Ihlea punctata (Forsk\xc3\xa5l, 1775) shows that there is no ground for the assumption that the species described as Ihlea asymmetrica (Fowler, 1896) is separate from I. punctata. Two undescribed taxa, reported upon in previous studies of the present author, are now fully described as new species: Cyclosalpa danae and Thalia rhinoceros.