igil] ASCIDIANS FROM THE COASTS OF CANADA. 1 23 



From 50 to 80 tentacles. Aperture of dorsal tubercle varying from 

 a transverse slit to a horseshoe-shaped opening. From 14 to 20 languets. 

 From 20 to 22 bars on each side, with a few rudimentary ones near dorsal 

 and ventral margins of pharyngeal wall. Stigma tic infundibula deep 

 and nearly square; the spiral of each with 5 or 6 turns, often slightly di- 

 vided into shorter stigmata, the divisions occurring at the angles of the 

 square. 



Intestinal loop of the usual form, placed across posterior end of 

 pharynx. Rectum long, reaching nearly to base of atrial siphon. Gonads 

 on both sides of intestinal loop, the testicular lobes, but not the ovary, 

 usually extending to beginning of rectum. 



Numerous specimens from Departure Bay, Burrard Inlet, Uclue- 

 let, Banks Island and Hecate Straits. 



This species differs from the last in the more anterior position of the 

 atrial aperture, the roughened test and the smaller number of longi- 

 tudinal bars. 



C. inflata sp. n. 



This is very similar to the preceding species. No intermediates 

 have been found. It was obtained only at Departure Bay, occurring 

 there in quantity at low tide and in very shallow water (8 fathoms or 

 less). The most characteristic feature is the great enlargement of the 

 atrium (the median part of the peripharyngeal cavity just beneath the 

 atrial siphon). As a result of this, the shape is more nearly cubical than 

 in the last species and the rectum is very much shorter (less than half 

 the length of the body). There is a smaller number of tentacles (40 to 

 60) and also of longitudinal bars (16 to 18). Many of the latter (es- 

 pecially dorsally) are represented only by T-shaped processes, the pharynx 

 not reaching, even in large individuals as complete a stage of develop- 

 ment as that of the last species. The testicular lobes do not extend as 

 far as the beginning of the rectum. The apertures are at the same level 

 and the surface of the test is roughened with small irregular processes. 



Genus — Chelyosoma. 



There have been divergent accounts of the position of the intestinal 

 canal in members of this genus. The most recent statements are that 

 the loop is sometimes on the right side of the body and sometimes on the 

 left side. As its position in other genera is quite constant, this seemed 

 rather remarkable. An examination of a large number of specimens 

 belonging to two species which occur on the West Coast and of a single 

 specimen of the type species from the East Coast has shown that, in all, 

 the loop is on the lower attached side of the body, which in this case cor- 

 responds for the most part with the right side of the pharynx, as the 



