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Bohn, J. M. and Heinzeller, T. 1999. Morphology of the bourgueticrinid and isocrinid aboral nervous system and its possible phylogenetic implications (Echinodermata, Crinoidea). ÐActa Zoologica (Stockholm) 80: 241-249.On the basis of semithin serial sections the aboral nervous system within the calyx of five bourgueticrinid and one isocrinid species was reconstructed using the computer programm NIH Image. The aboral nervous system of all bourgueticrinids belongs to a common type which is proposed to be called`Bathycrinus-type' (B-type), that differs from the`Isocrinus-type' (I-type). The morphology of the B-type and the I-type are described and differences are discussed. Together with the B-type there are now six aboral nervous system types well established and the consequences regarding phylogeny are discussed. Conclusions: 1) The morphology of the aboral nervous system may be a useful tool for the clarification of relationships between crinoid groups; 2) All known aboral nervous system types can be derived from the I-type, which seems to be the most primitive one; 3) The B-type aboral nervous system is probably a synapomorphic feature characterizing a monophyletic group within the Bourgueticrinida.

An examination of seven Antarctic brooding cucumariid and psolid holothurian species revealed a variety of characters all of them have in common: (1) All are gonochoric. (2) A genital papilla is present on the oral disc (permanent and digitiform in males). (3) Females brood their offspring in five anterior interradial brood pouches that are situated at the transition of body to introvert. (4) Multiple spermatozoa are always bundled to bunch-like spermato-zeugmata. (5) The spermatozoa have a fusiform head and a hollow cylinder-like mid-piece encircling the anterior end of the flagellum. This combination of characters so far is unique, and indicates a close relationship based on common origin. As a consequence, we unite all species sharing this set of synapomorphies in the genus Echinopsolus Gutt, 1990. The herewith included species are: E. acanthocola Gutt, 1990, E. acutus (Massin, 1992) comb. nov., E. charcoti (Vaney, 1906) comb. nov., E. koehleri (Vaney, 1914) comb. nov., E. mollis (Ludwig & Heding, 1935) comb. nov., E. parvipes Massin, 1992 and E. splendidus (Gutt, 1990) comb. nov.. Because the current assignment of Echinopsolus to the family Psolidae can not be retained, the genus is tranferred to the family Cucumariidae, as relationships to taxa within this family are obvious. The peculiar spermatozoa and spermato-zeugmata of all Echinopsolus species are described using light-and electron-microscopical techniques and the results are evaluated and discussed concerning their taxonomy and phylogeny.

Agassiz trawl and epibenthic sledge samples taken at abyssal depths in the Angola Basin (south-eastern Atlantic Ocean) during the expedition DIVA-1 with FS "Meteor" in July 2000 yielded a rich variety of Echinodermata: inter alia one stalked crinoid (Bathycrinus cf. aldrichianus Wyville Thomson, 1876) and altogether nine holothurian species, two of which are subspecies. One of these, Achlyonice longicornis spec. nov., is new to science, while all others have been described earlier: Deima validum validum Théel, 1879, Psychropotes semperiana Théel, 1882, Peniagone purpurea (Théel, 1882), Molpadiodemas atlanticus (R. Perrier, 1898), Molpadia liska Pawson, 1977, Protankyra brychia (Verrill, 1885), Siniotrochus myriodontus Gage & Billett, 1986 and Neolepidotrochus parvidiscus angolensis Bohn, 2005. All species collected are described and their known distributions are given. Finally, two crinoids and 21 holothurian species, so far known from the abyssal Angola Basin, are listed and their zoogeographical relationships are discussed.