ASTEROIDEA OF NORTH PACIFIC AND ADJACENT WATERS — FISHER. 



71 



7Vp«.— Cat. No. 21927, U.S.N.M. 



Type-locality. — Albatross station 4413, between Santa Catalina and Santa 

 Barbara islands, in 152 to 162 fathoms, on gray sand. 



Distribution. — Vicinity of Guatlalupe and Cerros islands, Lower California, 

 north to vicinity of Santa Catalina Island, and San Pedro, California; undoubtedly 

 ranging much farther south. Bathymetrical range, 47 to 162 fathoms. 



Specimens emmined. — The following is a list of localities from which one 

 hundred and fifty-four specimens have been examined: 



Specimens of Astropecten ornalissimus examined. 



Remarks. — ^This species differs from A. fragilis, A. regalis, A. verrilli, and A. 

 rubidus in the same respects as does A. californicus. 



Genus PSILASTER Sladen. 



Psilaster Sladen, Narr. Challenger Exp., vol. 1, 1885, p. Gil. Type, Astropecten andromeda Miiller 



and Troschel; Challenger Asteroidea, 1889, p. 221. 

 Bathybiaster Fisher (not Danielssen and Koren), Bull. Bur. Fisheries for 1904, vol. 24, June 10, 



190.5, p. 295. 

 riutonaslcr Ludwig (not Sladen), Mem. Mus. Comp. Zool., vol. 32, July 17, 1905, p. 30. 

 rhidiaster K(ehler, An Account of the Deep-Sea Asteroidea collected by Roy. Ind. Mar. Surv. 



Ship Investigator, Calcutta, April, 1909, p. 28. Type, Phidiaster agassizi Koehler. 



Diagnosis. — Disk small; rays five, high at base, tapering, pointed, with sides 

 perpendicular or arched inward towanl actinal surface; marginal plates massive, 

 plane, not tumid, separated by fasciolar grooves, either shallow or fairly deep; 

 superomarginaLs with or without large spinelets; inferomarginals regularly with 

 several enlarged spinelets, either appressed to ray or bristling, and in the form of a 

 perpendicular comb; exceptionally the inferomarginal spinules form two fairly 

 regular longitudinal series along ray; abactinal area with compact paxilla^, arranged 



