260 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



tentacles, and a plain dorsal lamina are characteristic of 

 the true C. echinata, while the Kara Sea form has 7 — 9 

 folds, 15 to 25 tentacles, and a series of dorsal languets in 

 place of a lamina — all points of agreement with C. villosa 

 from Puget Sound. 



The point in which Traustedt's species differs from 

 C. villosa is the spines on the outside of the test, which 

 are clearly seen in his figure to be branched in a stellate 

 manner, 7 to 9 large echinated branches arising from a 

 common peduncle or papilla, whereas, in our specimens 

 (7) of G. villosa, the echinated spines are not branched, 

 and so have no stellate appearance. 



I shall now give a re-description of Stimpson's species, 

 drawn up from my specimens dredged in the original 

 locality : — 



External appearance. Shape ovate, pyriform or cordate, 

 with the narrower end posterior, and sometimes attached 

 by a short stalk. Apertures both anterior, rather far apart, 

 both 4-lobed. Surface closely covered with long echinated 

 spines, which spring from small rounded elevations of the 

 test. These spines have no large branches, and are not 

 grouped in a stellate manner. Colour brownish grey. 

 Length 4 cm., breadth 3 cm., thickness 1 cm. 



Test thin but tough, smooth and shining on the inner 

 surface. 



Mantle not thick, but muscular, especially on the 

 siphons. 



Branchial sac with 8 folds on each side. Internal 

 longitudinal bars about 6 to 10 in a fold, and 2 or 3 in 

 the interspace. Stigmata running transversely, conse- 

 quently no meshes are present. 



Dorsal lamina a series of languets. 



Tentacles much branched, from 15 to 20 in number, 



