THE JOURNAL 



OF 



THE LINNEAN SOCIETY. 



A Eevision of the G-enera and great G-roups of the Ecbiuoidea. 

 By P. Martin Duncan, M.B. (Lond.), P.E.S., F.L.S., &c. 



[Eead 7th February, 1889.] 



Introduction : — the necessity for a Revision of the Fossil and Recent Genera 

 of the Class Echinoidea and for a reconsideration of the arrangement of the 

 great groups. —Definition of the Class Echinoidea and of its Subclasses the 

 Pal^echinoidea and the Buechinoidea. Remarks upon the Pal^echinoidea, their 

 Classification. — Definitions of the Orders and Genera. 



The last work of L, Agassiz and Desor, " Le Catalogue E-aisonne 

 des Pamilles, Grenres, et des Especes de la Classe des Echinides," 

 was published in the ' Annales des Sciences Naturelles ' during 

 1846-7, and was a magnificent conspectus of all their previous 

 labours in the classification of both the fossil and the recent 

 Echinoidea. The work formed the foundation of a vast super- 

 structure, which, however, soon separated into studies of the 

 fossil species and genera apart from those of the recent fauna. 

 Desor gathered together all the information regarding the fossil 

 forms up to 1858, when he published his ' Synopsis des Echinides 

 fossiles.' This standard work has been of great value to palaeon- 

 tologists. The history of the Zoology of the recent Echinoidea, 

 subsequently to the date of the ' Catalogue Raisonne ' and up to 

 1883, and also a previous ' Eevision of the Echini ' (1872-4) 

 were the contributions of Alexander Agassiz. The Eeports on 

 the Echini of the ' Hassler,' 1874, ' Challenger,' 1881, and ' Blake, 



LINN. JOUBN. — ZOOLOGY, VOL. XXIII. 1 



