BRISASTER TOWNSENDI. 179 



Lateroanal fasciole reduced to only a slender piece below periproct, or entirely wanting. 



Petals very large occupying most of upper surface of test, all nearly as wide as III; 



I and V half as long as II and IV or longer; greatest width of test in front of 



middle townsendi. 



Petals smaller and narrower; I and V usually i of II and IV but sometimes more; 

 greatest width of test at or back of middle. 

 Sternum not twice as long as wide. 



Petal III very wide, §-$ its own length; anal fasciole distinct; v. d. not 



\ length latifrons. 



Petal III not so wide, about I its own length; anal fasciole wanting or 

 faint; test distinctly elevated at apex, v. d. often far more than \ 



length moseleyi. 



Sternum nearly 3 times as long as wide; v. d. not | length kerguelenensis. 



Brisaster fragilis. 



Brissus fragilis Diiben and Koren, 1846. Skan. Ech., p. 280. 



Schizaster (Brisaster) fragilis Gray, 1855. Cat. Rec. Ech. Brit. Mus., p. 61. 



This is the well-known species of the Atlantic Ocean, but its distribution is 

 very peculiar. On the American coast it extends as far south as Florida at 

 depths in excess of 35 fms., but on the European coast it is not known south 

 of the Faeroe Channel. Yet it occurs in the region of the Cape of Good Hope! 

 I have at hand one of the Challenger specimens from that region and in spite 

 of Mortensen's and Doderlein's critical notes, I am unable to believe that it 

 differs from fragilis, the suggested distinctions being either too trivial or too 

 inconstant. 



Brisaster indicus. 



Koehler, 1914. Ech. Indian Mus. Spat., p. 201. 



Since this species is based on four very small specimens, 10 or 11 mm. long, 

 it is obvious that its real status is uncertain, but in view of its geographical 

 isolation at the Andaman Islands, it is probably a valid form. 



Brisaster townsendi. 



Schizaster townsendi A. Agassiz, 1898. Bull. M. C. Z., 32, p. 82. 



Schizaster (Brisaster) townsendi Mortensen, 1907. Ingolp Ech., pt. 2, p. 123. 



Plate 155, figs. 4, 6, 8. 



As Mortensen has examined the pedicellariae of this species, it is unneces- 

 sary to give any account of them. The large series of specimens in the Alba- 



