li*07] Ritter. — California Coast Ascidians. 9 



which the hody rests. No siphon nor orifices visible without re- 

 moving the covering of foreign particles. Length of longest spec- 

 imen, 4 cm. ; thickness of same, 2.3 cm. Other specimens of the 

 collection but little smaller. 



Test. — Thin and leathery after adhering particles are re- 

 moved; semi-transparent. Filamentous processes very numerous 

 and slender, but little branched, foreign particles clinging to them 

 throughout their length. 



Mantle. — No definite nniscle bands excepting around the ori- 

 fices. Here large and strong bands regularly disposed radially 

 ai'ound the orifices, uniform in length and terminating abruptly 

 at their distal ends ; also a narrow zone of circular fibres around 

 each orifice. The rest of the mantle containing an open mesh- 

 work of fine fibres (pi. 1, fig. 7). 



Branchial Apparatus. — Siphons entirely wanting. Orifices 

 not far apart, the branchial being well forward, the atrial near 

 the middle of the length of the body. On removal from the test 

 the orifices found to be slightly but unequivocally six-lobed 

 (branchial), and four-lobed (atrial). Branchial tentacles about 

 ten, of several sizes, the largest large and copiously branched. 

 Hypophysis-mouth a narrow ellipse directed somewhat obliquely 

 to the long axis of the animal. Peripharyngeal hand running 

 close to the anterior ends of the branchial folds. Ganglion a little 

 more than twice as long as broad, less than its length behind the 

 hypophyseal mouth. Dorsal lanmia a plain-edged rather broad 

 membrane (pi. 1, fig. 8). Branchial sac with six prominent folds. 

 Longitudinal vessels of the folds delicate and rather irregular in 

 num])ei' and course ; about five on each side of each fold, nearly 

 equally spaced from one another. Infundihula large, extending 

 full size to the edge of the folds and leaving little space between 

 them along the transverse vessels. Stigmata large everywhere; 

 little curved except as they extend around the infundibula. 



Intestinal Tract. — Situated on the left side at the extreme pos- 

 terior end of the animal ; loop a close one. Stomach not large, 

 nearly twice as long as broad, smooth-walled. Intestine very long 

 and thin, of uniform diameter throughout ; rectal half forming a 

 wide semi-circle; anus without lobes. Renal organ consisting of a 

 large brown, regular elongate central portion, surrounded by a 



