162 HAWAIIAN AND OTHER PACIFIC ECHINI. 



posterior petals relatively long; globifer- 

 ous pedicellariae with 4 teeth around 



terminal opening Tripylaster. 



Apex posterior; posterior petals relatively 

 short; globiferous pedicellariae with a 



single terminal tooth Brisaster. 



Test high, v.d. more than .60 length; genital 

 pores only 2. 



Lateroanal fasciole incomplete or wanting; 



petals not much sunken Hypselaster. 



Lateroanal fasciole complete, distinct; 

 petals especially III more or less 

 deeply sunken. 



Ambulacral pores in III in a double 



series Ova. 



Ambulacral pores in III in a single 



series Schizaster. 



Peripetalous fasciole follows closely the margins of petals 

 II and IV; all petals very deeply sunken; lateroanal 

 fasciole well marked; genital pores 2. 



Petals II and IV longer and wider than III; petals 

 not so deeply depressed as to be enterable only 



through narrow slits Moiropsis. 



Petals II and IV not longer and wider than III; 

 petals so deeply depressed as to be enterable only 

 through narrow slits Moira. 



Platybrissus. 



Grube, 1865. Jahresb. Schles. Gesell. Vat. Cult., 43, p. 61. 

 Type, Platybrissus roemeri Grube, 1865. hoc. cit. 



This is a monotypic genus of which almost nothing has been learned since 

 its original description. The specimen of the type species in the M. C. Z. col- 

 lection is apparently the holotype and so far as I have been able to learn the 

 only other specimen known is one belonging to Doderlein. Unfortunately 

 both specimens are bare tests. There is no clue as to the locality whence the 

 M. C. Z. specimen came, but Doderlein states (1911. Abh. Senckenb. Nat. 

 Gesellsch., 34, p. 237) that his specimen is from the Banda Sea. 



Amphipneustes. 



Koehler, 19(X). Bull. Acad. Rolgiquo, (?), 38. p. 817. 

 Type, Atnph&pntutfot loriaU Koehler, 1900. Loe. cit. 



This originally monotypic genus was based on a single specimen taken by 

 the Belgica in the Antarctic Ocean at a depth of about 334 fins. Subsequently 



