ASTEBOIDEA OF NOKTH PACIFIC AND ADJACENT WATERS — FISHEU. 45 



Variations. — There are three specimens from station 3002 which are diliicult 

 to classify satisfactorily. Two resemble ardicus but liave a larger disk, shorter and 

 broader rays, and larger superomarginals. The third much resembles anomalus, 

 and in the sum of its characters stands about midwaj' between the two specimens, 

 above referred to, and anomalus, which was taken at the same station. The aber- 

 rant specimens have inferomarginals resembling those of arcticus. R = .37 mm. 

 (largest specimen) ; r=15 mm.; K = '2.5 r. Breadth of ray at base, measured from 

 interradial line, IS mm. It is not improbable that this species hybridizes with 

 anomalus whenever the ranges overlap, and that the very aberrant specimens may 

 be explainetl i)y such a theory. 



Type-localiUj . — Oxfjord, Finmark, 100 to 150 fathoms. 



Distnhution. — The distribution of this species is evidently circumpolar. In the 

 Atlantic hemisphere it is found along the east coast of North America from lat. 

 38° to 45° N., and on the coast of Europe from south of Ireland, the Faroe Channel, 

 off Norway from Trondhjem to Finmark, and eastward to Barents Sea and the 

 Murman coast." In the north Pacific region the species ranges over Bering Sea and 

 south on the Asiatic side to Yezo, Japan. 



Specimens examined. — One typical from station 4792, vicinity of Commander 

 Islands, 72 fathoms, pebbles; two aberrant forms, 3602, vicinity Pribilof Islands, 

 Bering Sea, SI fathoms, green mud, sand; one from 5047, off Hokushu, Japan, 107 

 fathoms, dark gray sand, broken shells, pebbles. 



Remarks. — The specimen from near the Commander Islands agrees in most 

 particulars with an example from the coast of Maine (station 21, Cashes Ledge). 

 The Atlantic specimen has the raised ridges of inferomarginals at base of ray, 

 slightly wider. 



LEPTYCHASTER PACIFICUS Fisher. 



PI. 8, fig. 2; pi. 9, fig. 2; pi. 50, fig^. 1, la. 

 Leptychaster padfims Fisher, Proc. Wash. Acad. Sci., vol. 8, Aug. 14, 1906, p. 112. 



Diagnosis. — General form similar to that of L. arcticus (Sars). General form 

 flattened; rays evenly tapered, blimtly pointed; interbrachial angle slightly 

 rounded, but abrupt; abactinal surface subplane; margin of rays defined by 

 inferomarginal plates, rounded; superomarginal plates well developed, relatively 

 larger than in L. arcticus, forming a fairly conspicuous margin to abactinal paxillar 

 area; actinal surface slightly convex; paxilla? compact, the larger with about 

 twenty-five peripheral and thirty central spinelets; plates of papular areas Jobed; 

 papulae in fives and sixes about each; adambulatral plates with four or five furrow 

 spinules and on actinal surface two or tliree longitudinal series of about four similar 

 spinules. Rays five. R = 43 mm.; r=14 mm.; R = 3r. Breadth of ray at base, 

 16 mm. 



Description. — Abactinal paxillar area fairly compact, the paxillfe decreasing 

 in size toward center of disk, midradial line, and end of ray; smallest paxilliB in 

 center of disk, the largest on margin of area at base of ray. Paxillse similar in 



o Condensed from Ludwig, Fauna Arctica, vol. 1, p. 452. 



