122 THE VOYAGE OF H.M.S. CHALLENGER. 



Encope. 



Encope, Agassiz, 1840, Cat. Syst. Eotyp. 



Encope ema7'ginata. 



Echinodiscus emarginatiis, Leske, 1778, Kl. Add., p. 136. 

 Encope emarginata, Agassiz, 1841, Mon. Scut., p. 47, pi. x. 



Off Bahia 20 to 70 fathoms. 



PETALOSTICHA. 



Sub-order Petalosticha, Hieckel, 18G6, GenereUe Morphologie (emend.). 



Cassidulid.e. 



" Family Cassidulid^, Agassiz, 1847, C. E. Ann. Sg. Nat., vol. vii. p. 147. 



NUCLEOLID^. 



Sub-family Nucleolid*, Agassiz, 1847, C. R. Ann. Sc. I^at., vol. vii. p. 147. 



Echinolampas. 



EcMnolampas, Gray, 1825, Ann. Phil. 



It certainly is very unfortunate for Paleontological nomenclature that both Gray and 

 myself should have felt compelled to adopt the name Echhianthus for Clypeaster 

 rosaceus. Desor and D'Orbigny starting from different standpoints, the one in his zeal to 

 restore the old names of Breynius and the other with the idea of not abandoning names 

 of types which had become generally recognised among Echinologists, limited Breynius' 

 genera without any reference to the previous limitations of the same genera suggested by 

 Gray. Gray's suggestions were completely overlooked by Paleontologists, and the 

 confusion which might have been avoided has, I fear, been only increased by these subse- 

 quent attempts to reinstate old genera within limits which were not intended by the 

 original author. The limitations originally introduced by Gray, dating back as they do to 

 1825, have fully as much right to recognition as a similar attempt to reinstate the same 

 old genera within different limits dating from 1855. So that, even granting that it was 

 • not worth while to attempt to reinstate the genera of Breynius, it was worth while to 

 take into account the divisions adopted by Gray. But with the insufficient distinctions 

 now shown to exist between Echinantlms (fossil) and Echinolampas, it may be wisest to 

 retain Echinolampas alone for the group now known among Paleontologists as Echinan- 

 thus and Echinolampas. 



