70 WALTER GARSTANG, M.A. 



Perophora, Wiegmann. Jahresbericht, Archives, 1835, p. 309. 

 Ascidia, Fleming. Molluscous Animals, Edin., 1837, p. 202. 

 Perophora, Forbes and Hanley. Brit. Moll., 1853, p. 28. 



— Adams. Genera of Mollusca, 1858, ii, p. 596. 



— Giard. Recherches, 1. c, p. 615. 



— R. von Drasche. Die Synascidien, 1883, p. 8. 



— Herdman. Tunicata, Encycl. Brit., 9th Edit. 



— Cams. Prodr. Faun. Med., 1890, ii, pt. ii, p. 476. 



— Herdman. On the Genus Ecteinascidia, 1. c, p. 161. 



Zooids quadrangular or oblong, rarely pyriform, never cylindrical, 

 generally compressed from side to side. 



Test thin, membranous, without sterile stolonial tubes ; apertures 

 apart. 



Branchial sac rarely provided with rudimentary horizontal mem- 

 branes ; interserial papillae triangular or tubular ; papillae simple or 

 each provided near its extremity with an anterior and posterior 

 longitudinal process ; processes rarely fusing to form complete 

 internal longitudinal bars ; dorsal lamina, a rudimentary or well- 

 developed longitudinal membrane, supporting interserial languettes 

 compressed from side to side. 



Stigmata usually in four, rarely six, transverse rows. 



Stolons delicate, distinct, creeping ; branches generally alternate in 

 position. 



The species included within this genus are at present four in num- 

 ber — Listen (Weigmann), Hutchinsoni (Macdonald), viridis (Verrill), 

 and banyulensis (Lahille). Of these, P. banyulensis may prove not to 

 be distinct from P. viridis, as Herdman believes, while P. Hutchinsoni, 

 despite Macdonald's careful description and figures, will probably 

 be found on re-examination to present some structural characters not 

 included in the above generic diagnosis. 



In his recent paper on Ecteinascidia and its allies, Professor 

 Herdman has anticipated me in a description of the interesting con- 

 dition of the interserial papillae in P. viridis. I can quite confirm 

 his account by my observations on a number of specimens of a 

 Perophora which Professor Weldon collected in the Bahamas and 

 gave into my hands some time ago for description. Professor 

 Herdman rightly interprets the bifid or trifid papillae of P. viridis as 



