BRISSUS. 217 



is the West Indian species of the genus which Mr. Agassiz thought might become 

 the basis of a new subgenus and which Duncan made the type of Neopneustes. 

 But it is quite near the Hawaiian species placopetalus, and until we have adult 

 material of these two species it is better to treat them as congeneric. Whether 

 they are congeneric with pyramidalis is still another question. 



Rhynobrissus hemiasteroides. 



Rhinobrissus hemiasteroides A. Agassiz, 1879. Proc. Amer. Acad., 14, p. 211. 



I am satisfied that Tenison-Wood's species apicatus from the coast of 

 Australia between Port Jackson and Moreton Bay is identical with Mr. Agassiz's 

 from Tahiti, and Mr. Agassiz's name has a few months' precedence. Wood's 

 specimen was 64 mm. long and hence much larger than those Mr. Agassiz studied. 

 Whether this species is really congeneric with pyramidalis seems doubtful. 

 The single specimen available had but two pedicellariae, one rostrate with 

 valves .30 mm. long, and one tridentate with valves not quite that length, 

 and neither was in any way characteristic. 



Brissus. 



Leske, 1778. Add. ad Klein, p. xx. 

 Type, Spatangus brissus unicolor Leske, 1778, loc. cit. 



Leske proposed the name "Brissi" for the third (of four) "famihV's in 

 the genus Spatangus, and in this group he included only the single species, 

 no. 85, Spatangus brissus. If therefore the third section of Spatangus "Brissi" 

 (equivalent of course* to a subgenus) be raised to generic rank its type species 

 must bear the specific name brissus. But Leske's Spatangus brissus was, as he 

 himself recognized, a composite made up of at least four forms, which Lave 

 since been recognized as full species, under the varietal names given by Leske. 

 One of these maculosus ( = spatagus L.) was removed to Metalia by A. Agassiz 

 in 1872 and another ovatus is quite unrecognizable. Of the two remaining forms 

 we may well choose unicolor as the type of the genus and as the form which must 

 obviously retain the specific name brissus. The only way in which this change 

 of name can be avoided is by regarding the word "Brissus" in Leske's "Species 

 85. Spatangus Brissus," as not a specific but a subgeneric name, and this 

 course seems to do violence to Leske's obvious meaning as well as to common 

 sense. It is curious that Leske's fourth varietal name (latecarinatus) was 



