326 VERRILL 



{Leptopiychaster), which has been adopted by Sladen and many 

 other writers. The change seems to be uncalled for and pedantic. 



The type species is known to carry its eggs and young on the back, 

 under the paxillary spines. This has not been observed in either of 

 the northern species. 



LEPTYCHASTER ARCTICUS (Sars) Sladen. 



Astropeiten arcticus M. Sars, Reise Lofoden og Finmarken, Nyt Mag. Nat., 



VI, p. i6l, 1851. 

 Archaster arcticus Verrill, Amer. Journ. Sci., xvi, p. 214, 1878. 

 Leptopiychaster arcticus, var. elongatus Sladen, op. cit., p. 189, 1889. 

 Leptopiychaster arcticus Sladen, op. cit., p. 189. Verrill, Proc. Nat. Mus., 



xvii, p. 255. 1894; Amer. Journ. Sci., xlix, p. 133. 1895. Ludwig, Fauna 



Arctica, i, p. 452, 1900. 

 Leptychaster arcticus Fisher, op. cit., 191 16, p. 43, pi. viii, fig. i ; pi. ix, fig. 4. 



This well-known Arctic and North Atlantic species has been 

 recorded from the North Pacific by Fisher. It differs from the other 

 west coast species in having more slender rays (radial ratio, about 

 1 : 3.25) and smaller superomarginal plates, about forty on each side 

 of a ray, which form only a narrow margin to the disk. The infero- 

 marginals are quite oblique and have a narrow carina-like ridge and 

 wide fasciolate furrows. Dr. Fisher has given a detailed description 

 of North Pacific specimens. 



In the North Pacific, according to Fisher, it ranges from Bering 

 Sea to Yezo, Japan, in 72 to 107 fathoms. 



On the eastern coast of North America it is most frequent in 80 to 

 200 fathoms. Its recorded ranges in depth are from 50 to 965 

 fathoms (1350 fathoms, Sladen). 



It was taken by the U. S. Fish Commission parties at twenty-three 

 stations, from N. lat. 45° 14' to 38° 29'. It always occurred in small 

 numbers. It is found off the northern coasts of Europe, south to 

 Norway and off Ireland, and northward to the Arctic Ocean and 

 Barents Sea. It is evidently circumpolar. 



LEPTYCHASTER PACIFICUS Fisher. 



Plate Lxxiv, figure 5. 



Leptychaster paciAcus Fisher, Proc. Wash. Acad. Sci., viii, p. 112, 1906; op. 



cit., 191 16, p. 45, pi. VIII, fig. 2; pi. IX, fig. 2; pi. L, figs. I, la. 

 Leptychaster millespina Verriu,, op. cit., 1909, p. 553. 



Form regularly stellate, with five tapering, acute rays. The radii, 

 in the specimen here described, are about 14 mm. and 35 mm.: 

 ratio, 1 : 2.5 : often i : 3. 



