ECHINOIDBA. II. 



123 



to be given, if the name Amphidetus can not be retained, which seems not impossible, though 

 Agassiz (Rev. of Ech. p. 15) thinks it could not be retained, as it is a synonym of Echinocardium 

 Gray — but of Echinocardium in its later modified sense. — Tbese are, indeed, so disagreeable changes 

 in nomenclature that I will not propose to make them, the more so as so eminent authorities as 

 Prof. Ludwig and Dr. F. A. Bather, before whom I have put the whole question, are of opinion 

 that it is not absolutely needed. I will then retain the names in the sense in which they are used in 

 ^Revision of Echini , but I fear it is not in accordance with the strict rules, and I, lor my part, sincerely 

 regret that Agassiz, who has traced the history of these names and given it fully in his most ex- 

 cellent Chronological List in the « Revisions, did not make these changes in the nomenclature on that 

 occasion. It might have been done at that time without causing much trouble. To now change Moira 

 to Echinocardium or Schizaster, and Schizaster in its present sense to Ova or even to Spatangus 1 would 

 not fail to cause a great deal of confusion. 



The genus Schizaster should then be thus subdivided: 



Subgen. Paraster Pomel. Test not very high. Petals and frontal ambulacrum much deepened, 

 apical system posterior; four genital pores. (Globiferous pedicellariai unknown.) 

 Species: gibbertdus Ag., Savignyi Fourtau. 



Subgen. Schizaster s. str. (Syn. Nina Gray). Test very high; petals and frontal ambulacrum 

 much deepened; apical system posterior; two genital pores. The globiferous pedicellarise with a circle 

 of teeth round the terminal opening. 



Species: canaliftrus (Link.), laciuwsus (L), orbignyanus A. Ag., Edwardsi Cott 



Subgen. Tripylaster Mrtsn. Test low; petals and frontal ambulacrum not much deepened; apical 

 system subcentral; three genital pores. Globiferous pedicellarise with four teeth round the terminal 

 opening. 



Species: Philippii Gray. 



Subgen. Brisaster Gray. Test low; petals and frontal ambulacrum not much deepened; apical 

 system posterior (or subcentral); three genital pores. Globiferous pedicellarise with a single large tooth 

 at the point of the valves at one side of the terminal opening. 



Species: fragilis (Dub. Kor.), capensis Stud., Moseleyi A. Ag., latifrons A. Ag., Townsendi A. Ag, 

 antarcticus Doderlein. 



28. Spatangus purpureus O. F Midler. 



PI. II. Figs. 8, 12, 14, 16. PI. XVI. Figs. 1—2, 5—10, 22, 24—25, 27, 29, 31-32, 34. 



Svnonvms: Spatangus meridionalis Risso. 



— spinosissimus L. Agass. 



— Regincr Gray. 



1 Lambert: Description des Echinides fossiles de la province de Barcelona. Mem. Soc. geol. de France. IX. 1902. 

 p. 55. Xote. 



16* 



