642 PROF. F. J. BELt ON THE GENUS PSOLUS. [NoV. 14, 



of Semper' s voyagings are among the chief treasures of zoological 

 and anatomical literature. 



While this last-mentioned work was passing through the press, 

 Emil Selenka selected a comprehensive revision of the known Holo- 

 thuroidea as the subject of a philosophical dissertation for the docto- 

 rate ; to this and to the descriptions of Prof. Ludwig the student of 

 German literature will always have recourse. 



In this, as in other divisions of the Radiata, the zoologist owes 

 much to the long-continued researches of Professor Verrill, whose 

 chief work on Holothurians was unfortunately, and strangely enough, 

 progressing simultaneously with those of Semper and of Selenka. 



Coming at once to the genus Psoitis, we find that some incon- 

 venience has arisen from this simultaneous work ; for neither of the 

 German naturalists was able to take any note of the formation by 

 Verrill of two genera allied to Psolus ; and we have not, therefore, 

 their opinion on the value of the generic distinctions by means of 

 which Lophothuria and Lissothuria are added to the Psoline sub- 

 family — though we have, perhaps, some indication of Prof. Semper's 

 views in the remarks that he makes on the new genus Stolinus 

 formed by Selenka. 



The Holothuroidea form no exception among animals ; side by 

 side with the study of their natural history we have, unfortunately, 

 to make our way through that rapidly growing maze designated 

 " synonymy." I can see no advantage in retailing, at second hand, 

 the references to earlier writers who have more or less correctly 

 identified species, which references themselves are not without 

 exception exact. I propose therefore to give for the sake of com- 

 pleteness one, and probably the most suitable, reference for each 

 species. 



In the first place, however, it will unfortunately be necessary to 

 detail at length the history of a generic name which has attained 

 almost as great a vogue as Psolus itself, and which has, even lately, 

 been used in zoological literature. Prof. Studer (Monatsb. Ak. 

 Berl. 1876, p. 452) doubtless, like myself (P. Z. S. 1881, p. 100), 

 has used for Cuvieria antarctica the name by which that species is 

 best known, without at the time entering upon a close bibliographical 

 investigation. 



In the Animal Kingdom there are four claimants to the name 

 Cuvieria ; but this, of course, is not by itself a reason why we should 

 cease to make use of it for an Echinoderm. So far as 1 can discover, 

 the first time that the name appeared in print in association with 

 the Holothuroidea was in 1817 ^ when Cuvier wrote, " Celles que 

 Peron avait nomme'es Cuvieries." Peron, however, does not seem 

 to have ever quite definitely made up his mind as to what genus or 

 group should be dignified by association with the name of the illus- 

 trious anatomist. Several years earlier he had applied the name to a 

 Medusa (Voyage, Atlas, pi. xxx. fig. 2) : a little later than this he 

 published, in conjunction with Lesueur, a 'Tableau des Medusesj' and 



' Regne Anim. iv. ^. 22, note (1) ; and see pi. xv. fig. 9, where cuvieria is usecl 

 a^ a specific name. 



