DESCRIPTIONS OF NEW SPECIES OF RECENT UNSTALKED CRINOIDS FROM THE NORTH PACIFIC OCEAN. By Austin Hobart Clark, Of the United States Bureau of Fisheries. T\iif< paper is based upon material collected by the United States Fisheries steamer A/I)afross in the Pacilic Ocean north of Mexico and southern Japan. All but two of the species were collected on the recent Japanese cruise in the Bering' Sea and about Japan, The Eschrlcht'ii group is best represented in regard to numbers, with over 1,750 specimens, mostly of Bering Sea and eastern Pacific forms. Unfortunately, Antedon eschriehtii var. maxima is so large (about 3 feet in diameter) that on the last cruise, although we obtained it in enormous numbers — on one or two occasions, in fact, there was very little else in the trawl — we found it impracticable to preserve an extensive series. The species of this group in the eastern Okhotsk Sea, off eastern Japan, off the Pacific-American coast, and in the Bering Sea are all remarkable for the strong overlapping of the arm joints, which have serrate distal edges, a fact which was first noticed for this district by Hartlaub in Antedon tanneri from Panama. The lower pinnules also have a distal comb, resembling that in some species of Coniatida, but much longer than is usual in that genus. Another interesting fact is that the species from the western American coast all have the third syzygy in the fourteenth brachial and not in the twelfth, as do those from the Bering Sea and Asiatic coast. The dis-tal intersyzygial interval in the North Pacific species (excepting' those from southern fbipan and the Japanese Sea) is almost invariably two joints, whereas in most of the others it is three. All these species will be more fully described and figured in my report on the North Pacific crinoids. The following keys have been prepared with reference to all of the described species in the respective groups, and it is believed that the information given in them is amply sufficient to differentiate the new species from any of those given in the Challenger reports or subse-quently described. Proceedings U. S. National Museum, Vol. XXXlll— No. 1559. 69
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