191''] Eitter-Forsyth: Ascidians of Southern CaUfvriiia 455 



Branchial system. — Siphons described above. Branchial tentaclas: 

 very long and slender and of about the same size, varying in number, 

 the larger individuals having as many as 150. Hypophysis {hy., pi. 

 41, fig. 25), small and either oval or horseshoe-shaped with opening 

 directed forward. Ganglion mass {gl.) separated by several times 

 the length of hypophysis-mouth from the hypophysis (pi. 41, fig. 25). 

 Dorsal lamina {d.l.) a broad membrane, broader posteriorly than 

 anteriorly, provided with transvei-se ribs which project slightly past 

 the edge ; a kiv minute teeth between these pro.iections. The lamina 

 extends beyond the opening of the esophagus to the end of the sac. 

 Branchial sac extends the entire length of the animal. Internal 

 longitudinal vessels bear papillae at their intersections with the trans- 

 verse vessels. In a large individual sixty internal longitudinal vessels 

 and seventy transverse vessels were counted. No intermediate papillae 

 present; ends of papillae curve toward the dorsal lamina and have a 

 bulge on the concave surface. Plications in branchial membrane 

 fewer than the longitudinal vessels. Meshes rectangular, a little 

 longer than wide, each containing about three stigmata. 



Digestive system (pi. 41, fig. 24). — On left side of branchial sac. 

 About one-sixth of the branchial sac extends behind the digestive 

 apparatu-s and about one-third in front of it. Mouth of esophagus 

 about one-fourth the length of branchial .sac from its posterior end. 

 Esophagus sharply curved to enter the stomach. Stomach (s., pi. 

 41, fig. 24) about twice diameter of intestine at its esophageal end, 

 but gradually tapering to intestine at the other end ; long axis at right 

 angles to that of sac ; wall with about twelve, wide, orange-colored, 

 longitudinal folds. From the stomach the intestine runs anteriorly 

 and then curves in such a fashion as to form the letter S reversed. 

 Smooth-edged anus close to base of atrial siphon. A renal gland 

 ramifies over the rectal limb of the intestine. 



Reproductive system- (pi. 41, figs. 24 and 26). — Peculiar widely 

 branched ovary ramifies over whole inner surface of that part of 

 intestinal loop which lies anterior to stomach. Testis lobes, much 

 smaller and more finely branched than those of ovary, spread espe- 

 cially on inner surface of stomach and to some extent on both surfaces 

 of intestinal loop. White vas deferens and oviduct run side by side 

 along posterior side of rectum, the vas deferens lying between oviduct 

 and rectum, both ending near the anus. 



Specimens with sperm ducts enlarged and with eggs in their ovi- 

 ducts were taken in February at San Pedro, Santa Cruz, and La Jolla; 

 in May at Half Moon Bay; in June at San Clemente, and in July at 

 San Pedro. 



A. californica lielongs to the MeiituJa. section of the genus Ascidia. 

 this section being considered as characterized primarily by the exten- 

 sion of the branchial sac and dorsal lamina behind the esophageal 

 mouth. But within this section it seems to be sharply set off from any 

 species hitherto described. So far as we are able to ascertain, the 

 fine pectination of the lobes of the atrial orifice (pi. 41, fig. 27) is 

 entirely unique. The form and distribiition of the ovary also con- 



