I20 Transactions of the Canadian Institute. [vol. ix 



Ritter from Alaska, but differs from it in the number of stigmata in each 

 mesh, in the number of plications between successive bars and probably 

 also in the number of bars. 



A. Columbiana sp. n. 



Oblong, laterally flattened, attached by the entire left side. Up to 

 4.5 cm. in length, 3.5 cm. in width and 2 cm. in thickness. Apertures 

 placed as in last species. Surface more or less roughened, with numerous 

 short papillae, which differ greatly in size in several varieties of this 

 species which occur. Those near the apertures are always very distinct 

 and longer than the others. Musculature as in last species. 



From 20 to 45 tentacles. Prebranchial zone smooth. Aperture 

 of dorsal tubercle horseshoe-shaped, the horns frequently bent inwards 

 or outwards. Ganglion directly behind tubercle. Dorsal lamina strong- 

 ly ribbed, its margin with teeth corresponding to the ribs and occasionally 

 from I to 5 indistinct intermediate teeth. From 19 to 24 bars on the 

 left side and from 21 to 26 on the right. From i to 2 plications be- 

 tween successive bars. From 4 to 20 stigmata in each mesh. 



Stomach with from 12 to 22 shallow folds; intestine usually with 

 typhlosole. Anus at level of anterior end of intestinal loop or somewhat 

 behind it. Ovary chiefly on right side of first part of intestine. Testi- 

 cular lobes on left side of loop and on both sides of stomach. Oviduct 

 passes across lower (left) side of last bend of intestine and then along 

 posterodorsal border of rectum. 



Numerous specimens from Departure Bay, Ucluelet and Port Simp- 

 son. 



Differs from Ascidiella incnistans Herdman from Puget Sound in 

 the plain prebranchial zone and the toothed condition of the dorsal 

 lamina. Ascidia adhcsrens Ritter is without the papillated surface and 

 the peculiar course of the oviduct. Its closest ally is A. prunum (Miiller) 

 from the North Atlantic, which differs from it chiefly in the absence of 

 the papillae of the surface, and in the smaller number of bars (rt. 18 to 

 20, It. 15 to 19). 



A. paratropa sp. n. 



Short cylindrical, attached by small area at posterior end. Up to 

 II cm. in length and about 4.5 cm. in diameter. Oral aperture terminal, 

 7-lobed, turned toward the right side; atrial aperture, 6-lobed, at the end 

 of a short siphon which extends from the anterodorsal angle to a point 

 in front of the level of the oral aperture. Surface with large irregular 

 tubercles. Musculature, extensive on the right side, consisting chiefly 

 of longitudinal fibres ; on the left side, longitudinal fibres from the 

 siphons extend nearly to intestinal loop. 



