PEROPHORA ANNECTENS. 39 



recognized its intermediate position between the simple 

 and compound Ascidians, because of its power of repro- 

 ducing by budding, and in conclusion he says: " Je 

 proposerai aussi de donner a ce groupe intermedaire le 

 nom de : Section des Ascidies sociales " (p. 266). 

 And in this new section he placed also the one species of 

 Perophora then known. The two divisions of Savigny 

 were retained, with simply the substitution of the name 

 "Ascidies" for " Tethys." 



These three co-ordinate sections, thus established by 

 Milne-Edwards, were recognized by many writers, and 

 not particularly opposed by any, until Herdman's ('80) 

 preliminary report on the Tunicates collected by the 

 Challenger Expedition was made. In this collection this 

 author discovered a new genus, belonging to the same 

 family as Clavelina, named by him Ecteinascidia, which 

 differs from Ciona, a genus of simple Ascidians, 

 chiefly in the fact that it reproduces by budding. But 

 he afiirms that both Ciona and Ascidia are sometimes 

 found to possess stolons ('82, p. 238). He concluded 

 that the transition between the '■'Ascidies simples^' and 

 the '-'•Ascidies sociales " of Milne-Edwards is so complete 

 that the latter can no longer be regarded as a natural 

 group. He therefore discarded it and united all the 

 genera included in it (Herdman, '91, p. 599", and Gars- 

 tang, '91, pp. 50, 57 and 62), in one family, the Clavel- 

 inida? of the Ascidice Simplices. 



Finally, Garstang ('91, pp. 48 and 49) declares it as his 

 belief that " the division of the Ascidiacea into the sub- 

 orders Ascidice simplices, Ascidice corn-posit ce and Ascidia 



* The coujectnre here made by Prof. Herdman, that Clavelinopsis rubra 

 Fewkes, from the Califoruia coast, does not belong to the Clavelinida?, is 

 correct. It is not a Boltenia, however, biit a Styc-la, probably au uude- 

 scribed species, though I have not yet studied it with sufficient care to saj- 

 with certainty. 



