igil] ASCIDIANS FROM THE COASTS OF CANADA. 139 



resembling Ascidiella. From the latter it differs in having papillae on 

 the bars and in not having renal vesicles. It is thus intermediate be- 

 tween Phallusia and Ascidiella. The ganglion is close to the dorsal 

 tubercle and there are no intermediate papillae. In the absence of 

 renal vesicles, it resembles some Phallusice. As if to offset this lack of 

 vesicles, there is a very great development of what appears to be the py- 

 loric gland. This forms a thick layer of coarse branches, covering all 

 parts of the intestinal canal 



P. obliqua (Alder), 



Syn. Ascidia mollis Verrill, Amer.J. Sc, ser. Ill, vol. 7, p. 409. 



This can be distinguished from the preceding species by the thinner 

 test (which is more collapsible), the more numerous (about 50) longitu- 

 dinal bars, and the course of the genital ducts (not crossing last bend of 

 intestine), as v/ell as by the differing generic characters. 



Large numbers were dredged at various points and depths near 

 Grand Manan and occasional specimens were obtained in the approaches 

 to Passamaquoddy Bay. 



Chelyosoma macleayanuni B. & S. 



Syn. Ascidia geometrica Stimpson, Proc. Bost. Soc. N.H., vol. IV, 

 p. 229. 



A single specimen was obtained in the approaches. It is rather 

 unusual in the asymmetry of the plates of the disk. Those of the left 

 side are larger than those of the right and two additional plates are inter- 

 posed between the middle and posterior marginal plates. In both these 

 respects, it approaches C. columbianum of the West Coast. 



Caesira papulosa (Verrill). 



Syn. Molgula papulosa Verrill, Am. J. Sc, ser. 3, vol. i, p. 57. 



Surface with numerous radicoid filaments, those on the siphons being 

 quite short. Siphons quite variable in length, frequently as long as the 

 diameter of the body, nearly equal. 



From 15 to 25 bipinnate tentacles. Aperture of dorsal tubercle 

 horseshoe-shaped; opening between horns directed backwards. Dorsal 

 lamina of medium width, not extending beyond oesophageal aperture ; 

 its margin is coarsely toothed. Six folds on each side of pharynx. Pos- 

 terior end of each fold coarsely toothed along its free border. Bars on 

 both sides of each fold, as many as 8 on a fold, the dorsal bars weak. 



Intestine forming a double loop. Outer lip of anus with about a 

 dozen rounded lobes. Gonads elongated, the right horizontal, the left 

 oblique and filling the secondary loop of the intestine. Oviduct of me- 

 dium length, projecting upward from posterior end of gonad and ending 

 at base of atrial siphon. Each ovary with an upper and lower row of 



