497 



species, — S. gibbsii (Stimps.); and two stalked species, 

 — 8. montereyensis (Dall) and 8. costatum (Hrtmyr.). 



Section II. 

 More than two gonads, at least on the right side. Surface 

 of body fairly smooth and with large irregular folds. Short 

 species. 8. plicata (Les.), *S. pinguis Hrdmn., *S. stoloni- 

 fera Hrdmn. 



C 2 . Ducts of gonads turned ventrally and opening near endo- 

 style (Fig. X, right side). 



Genus Katatropa Huntsman. Type, — K. vancouverensis 

 Hntsmn. 



Four pharyngeal folds on each side. 

 Open interval of dorsal tubercle directed toward left. 

 Two gonads on each side. 



Spinules truncate or acicular. (Fig. XIII, 4 and 6). 

 The species of this genus are not as robust as those of 

 Styela. The oral tentacles are fewer and the testes show 

 less branching, (xarà, down and xqo7tv n a turning, refer- 

 ring to the gonads.) 



Section I. 



Testes short and usually somewhat lobed (Figs. IV upper, 

 VI, 2 and IX, 2). 

 Spinules truncate (Fig. XIII, 4). 



In this section there are two short species, — K. vancou- 

 verensis Hntsmn. and K. uclueletensis Hntsmn. ; and one 

 stalked species, — K. yakutatensis (Ritter). 



Section II. 

 Testes very long and without lobes (Fig. IX, 4.) 

 Siphonal spinules acicular (Fig. XIII, 6). 

 The single species, K. greeleyi (Ritter), is a stalked form. 

 Dr. Hartmeyer considers this species to be identical 

 with the Ascidia clavata of Pallas, relying upon the very 

 close external similarity. As there is a series of stalked 

 forms, which are often indistinguishable externally and 

 yet have very marked internal differences, I prefer to leave 

 the question open until the distribution of the North Pa- 

 cific stalked species has been studied more thoroughly. 

 I am in entire accord with Prof. Ritter who has recog- 

 nized three stalked species on the American side of the 

 Pacific. The three species are quite distinct. 



Zoolog. Auzeiger. Bd. XLI. 32 



