248 DISCOVERY REPORTS 



a papilla (there being a pair close together) in each constricted actinal interradial 

 area. 



Type locality. St. 170. Off Cape Bowles, Clarence Island, 342 m., rock, i specimen. 



Genus Diplasterias Perrier 



Diplasterias Perrier, Comptes-rendiis, cvi, no. 11, 1888, p. 765; 1891, p. 77. Type Diplasterias liitkeni 

 Perrier. — Fisher, Smithsonian Miscell. Coll., Ln, 1908, p. 89 (error in assignment oi sulcifera as 

 type); 1930, p. 229. 



Podasterias Perrier, 1894, pp. 107, 108; 1896, p. 35. Type Diplasterias liitkeni Perrier (not Podasterias 

 Perrier, 1891, p. 160). — Fisher, 1923, p. 603; Zool. Anz., XXXin, 1908, p. 358. 



Koehleraster Fisher, 1922, p. 596; 1930, p. 234. Type Anasterias octoradiata Koehler. 



Bathyasterias Fisher, 1930, p. 231. Type Asterias vesiculosa Sladen. 



Diagnosis. Adambulacral plates diplacanthid, the spines without attached pedicel- 

 lariae; abactinal skeleton irregularly reticulate; the plates with one to several slender 

 spines surrounded by a collar of pedicellariae and more or less heavily sheathed with 

 membrane which usually obscures skeleton, or without spines; marginal plates well 

 developed; superomarginal spines i or 2, conspicuous, clearly differentiated from 

 abactinal and surrounded by pedicellariae; inferomarginal spines usually 2, sporadically 

 3, bearing pedicellariae and forming definite longitudinal series separated from supero- 

 marginals by a well-defined intermarginal channel; actinal spines with attached pedicel- 

 lariae, in I longiseries (actinals exceptionally spineless) ; 2-4 pairs of contiguous postoral 

 adambulacral plates ; not fissiparous ; gonads opening ventrally ; young brooded by adult ; 

 straight pedicellariae lanceolate, typically not enlarged nor unguiculate. Differing from 

 Anasterias in having a stronger abactinal skeleton and diplacanthid adambulacral plates. 



Remarks. In the first reference to Z)/^te/mfl^( 1888) Perrier cites D. liitkeni Ferrier and 

 D. steifieni Studer as species which brood their young. He adds : " Je classe dans le genre 

 Diplasterias \es Asterias qui ont deux rangees au moins de piquants adambulacraires." 



In the Cape Horn report, published three years later, Diplasterias is entered as a 

 new genus, with the same diagnosis. Five species are enumerated and described: 

 D. sulcifera (Perrier, 1869), D. loveni Perrier, D. liitkeni Perrier, D. spinosa Perrier, 

 D. steineni (Studer). 



Diplasteriaswas thus formally published in connection with definite species from which 

 a type may be selected. If the first reference is to be regarded as a nomen nudum, as I 

 suggested in 1908 (Fisher, 1908, p. 89), the enumeration of D. liitkeni and D. steineni is 

 useful as an indication of the species which Perrier had in mind for his new, if somewhat 

 indefinite, genus. While Perrier's Cape Horn report was in the press, Sladen used Perrier's 

 first species, D. sulcifera, for the type of Cosmasterias. My choice, in 1908, cf D. sulcifera 

 as the type of Diplasterias was ill advised, due to a strict adherence to the " first species 

 rule " for the determination of a type when none is indicated by the author. It seems to 

 me that the oldest known species, Asterias bra^idti Bell, which includes both Diplasterias 

 liitkeni and loveni (cited by Perrier in 1891) should be chosen, especially as D. liitkeni 

 appears in the first, or Comptes Rendus, citation. 



