ASTBROIDEA OF NORTH PACIFIC AND .U)JACENT WATERS FISHER. 55 



Young. — The smallest specimen has K = 7 miii.j and is arcuate-pentagonal 

 in shape. Wlien compared with very young anomalus, the latter are seen to have 

 fewer and much more massive marginal plates. The other differences between the 

 adults are not so obvious but occur in a slight degree. 



Type.— C&t. No. 24:58S, U.S.N.M. 



Type-locality. — Albatross station 4792, vicinity of Commander Islands, Bering 

 Sea, 72 fathoms, pebbles. 



Distribution. — The ])Iateau upon which the Commander Islands are situated. 

 Bathymetrical range 54 to 72 fathoms. 



Specimen,<i examined. — Fifty-seven from three stations, all in the vicinity of 

 Commander Islands: 4787, 54 fathoms, green sand, eleven specimens; 4788, 57 

 fathoms, green sand, forty-five specimens; 4792 (type-locality) one specimen. 

 Taken by the steamer Albatross, June 14, 1906. 



Remarks. — The only specimens among those assigned to anomalus which 

 approach dangerously near the present species are six, which are unfortunately with- 

 out locality. These have considerably narrower and more numerous superomar- 

 ginals than typical examples, and more numerous inferomarginals, but there is no 

 difficulty in distinguishing them at a glance from propinquus. ^Vhen placed next to 

 a series of the latter, their superomarginals are evidently much more conspicuous, 

 especially in the interradial angle, while the inferomarginals are neither so numer- 

 ous nor so short. Although the general form of the two is so nearly the same, the 

 spinulation of the aberrant ano-malus is typical, and not like that of propinquus. 



I was at first inclined to regard this form as a race of anomalus, but in the absence 

 of intergrades have classified it as a distinct species. It combines characteristics 

 of typical Leptychaster and the synonymous genera Parastropecten and Glyphaster. 



Genus ASTROPECTEN Gray. 



Astropecten Grat (from Linck, 1733) Ann. and Mag. Nat. Hist., vol. 6, Nov., 1840, p. 180. 



Type ,1. aurantiacus, designated for the first time, 1908. — Rshee, Smiths. Misc. Coll., vol. 



52, 1908, p. 93. 

 Stellaria Nardo, De Asteriis, Oken's Isis, 1834, p. 716. Type S. auranliaca. Invalidated by 



Stellaria M0ller. 

 Asterias Agassiz (not Linnseus), M6m. soc. sci. nat. Neuchatel, vol. 1, 1835, p. 168. 

 Crenaster d'Orbiqnt, Prodrome de paleontologie, 1850, vol. 1, p. 240. 



Diagnosis. — Rays normally five in number; abactinal surface flat, not arched; 

 actinal surface slightly beveled on sides; disk variable in size, usually medium 

 to small; rays usually long and tapered; marginal i)lates large, the inferomar- 

 ginals always broader than superomarginals and sometimes extending laterally 

 beyond them; inferomarginals armed with spinelets and a variable number of 

 spines which increase in size toward the edge of ray; superomarginals, in addition 

 to small granules or spinelets, may also bear tubercles or cnlargetl spines extending 

 in one or two complete or interrupted rows along ray; or enlarged spines may 

 be entirely absent; exposed surface of consecutive marginal plates separated 

 by deep fasciolar grooves lined by minute capillar}' spinelets, those grooves acting 

 as percolaters or filters; abactinal area covered with true paxillte; papulae single, 

 usually absent from a narrower or wider midradial line, and from center of disk; 



