ASCIDIANS COLLECTED IN PUGET SOUND. 259 



(L.), but the spines are distinctly different in form and 

 arrangement in Traustedt's figure from what our specimens 

 show, and so the two are probably best regarded as closely 

 allied representative species. 



There are now five allied, somewhat similar, echinated 

 Cynthias known to me, which form a group extending 

 over most of the world, from the Arctic regions to 

 Australia, and found in both the Atlantic and the Pacific. 

 They are : — 



1. C. ecJiinata (L.), in North- West Europe. 



2. (?) C. ecJiinata (L.), Traustedt, in Kara Sea, Arctic. 



3. C. villosa, Stimp., in Puget Sound, N. Pacific. 



4. C. Jiilgendorfii, Traust., in Japan. 



5. C. spinifera, Herdm., in Port Jackson, Australia. 



Cynthia castaneiformis, v. Dr., is another allied form; 

 while Ascidia {? Cynthia) spinosa, Q. and G-., Ascidia 

 villosa, Fabr., and Cynthia villosa, Kupf., are very doubt - 

 ful species, in regard to which we have not sufficient 

 information. 



Alder, in 1863, first pointed out the remarkable fact that 

 the stigmata in the branchial sac of Cynthia ecJiinata 

 have their long axes transverse in place of longitudinal, 

 so that they run at right angles to the folds and internal 

 longitudinal bars, in place of parallel to them as in nearly 

 all Ascidians. This peculiar condition of the branchial 

 sac is found in the first three of the above-named species, 

 while in C. Jiilgendorfii, from Japan, and C. spinifera, from 

 Australia, the stigmata are normal. 



It is clear that the form from the Kara Sea, described 

 by Traustedt in 1886 as C. ecJiinata (L.), is distinct from 

 that species. His description does not agree with his 

 own diagnosis (which was correct) of G. ecJiinata given in 

 1880 from Danish specimens. Six branchial folds, 12 



