A new abyssal genus of the family Ophiuridae (Echinodermata : Ophiuroidea) Gordon L. J. Paterson Department of Zoology, British Museum (Natural History), Cromwell Road, London SW7 5BD Introduction A new genus of abyssal ophiuroid from the NE Atlantic belonging to the subfamily Ophiurinae of the family Ophiuridae is described. Its relationship to the genera Ophiotrochus and Bathylepta is discussed and justification given for the transfer of these two genera from the Ophioleucidae to the Ophiurinae,. both of which are rediagnosed. Uriopha is the fourth purely abyssal genus belonging to the family Ophiuridae to have been discovered in recent years, Perlophiura Belyaev & Litvinova, 1972, Abyssura Belyaev & Litvinova, 1976 and Bathylepta Belyaev & Litvinova, 1972 are the other three. It is perhaps slightly surprising that a new genus should be found in what could be considered a well investigated region. This might be due to the small size of the specimens resulting in their being overlooked by past researchers. The specimens of Uriopha form part of a collection of deep sea ophiuroids made by the Institute of Oceanographic Sciences' Discovery Investigations off North West Africa. Systematic descriptions URIOPHA gen. nov. DIAGNOSIS. A genus of the subfamily Ophiurinae, family Ophiuridae, with the disk completely covered by granules obscuring the plates beneath; the disk is convex or even domed; no arm combs or genital papillae are developed; the jaw has a spiniform apical papilla flanked on each side by oral papillae which becomes more blocklike distally; the adoral plates are long and thin; the oral shields are small and triangular; the second oral tentacle pore emerges superficially, away from the mouth slit; the tentacle pores are round, distinct and occur along the whole arm length, each has one large rounded scale and sometimes a smaller indistinct scale underlying it; there are two conical appressed arm spines on each lateral arm plate beyond the disk. TYPE-SPECIES. Uriopha ios sp. nov. DERIVATION OF NAME. Uriopha is an anagram ofOphiura, a genus of the Ophiuridae, and ios is derived from the initials of the Institute of Oceanographic Sciences. Uriopha ios sp. nov. Fig. 1 The eleven individuals of the type series have disk diameters of 3-4 mm. Viewed from above the disk is round to subpentagonal; in side view it appears high and in many specimens domed. A dense coating of granules, each about 0*04 mm in diameter, covers the dorsal surface and ventral interradial areas, obscuring the plates, including the oral and adoral shields but not the oral plates. The underlying dorsal plates are numerous, small and slightly imbricated, more so in the domed specimens. Except for the centrodorsal plate in some specimens, the primary rosette is usually indistinct. The radial shields are irregular though Bull. Br. Mm. not Hist. (Zool.) 38 (4): 211-218 Issued 25 September 1 980 211
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