191 1 ] ASCIDIANS FROM THE COASTS OF CANADA. 1 21 



From 15 to 30 rather short tentacles. Prebranchial zone smooth. 

 Aperture of dorsal tubercle as in last species; horns may be slightly coiled. 

 Ganglion about width of peripharyngeal groove behind tubercle. Dorsal 

 lamina ribbed on left side, its margin irregularly toothed, the largest 

 corresponding to the ribs. On right side of oesophageal aperture and 

 extending posteriorly is another lamina also toothed. From 28 to 34 

 bars on the left side and from 32 to 42 on the right. From i to 1.5 pli- 

 cations between successive bars. From 4 to 12 stigmata in each mesh. 



Stomach with from 40 to 46 shallow folds; intestine with typhlosole; 

 intestinal loop directed forwards but not bent toward dorsal side. Ovary 

 in intestinal loop, on both sides of loop anteriorly and on right side of 

 stomach. Testicular lobes in the loop and on both sides of posterior 

 part of loop, as well as on both sides of stomach. Gonoducts pass along 

 posterior side of last bend of intestine. 



About 30 specimens from Departure Bay, Ucluelet, Banks Island 

 and Goose Island, in from 5 to 20 fathoms. 



No Phallusiid that has been described seems to have the peculiar 

 shape and tubercles of this species. Ascidiella griffini Herdman from 

 Puget Sound may be near it, but, as described, it differs in shape, char- 

 acter of surface, number of tentacles (60-70) and the presence of pre- 

 branchial papillae. 



Genus — Phallusia Savigny (sens, restr.) 



Syn. Ascidia seu Phallusia auct. part. 



This genus may be restricted to those forms that can be grouped 

 around the type species (Ascidia mentula Miiller ?) and which have the 

 pharynx extending behind the posterior border of the stomach, longi- 

 tudinal bars with papillae, dorsal lamina extending behind oesophageal 

 aperture, ganglion a considerable distance behind dorsal tubercle and 

 renal vesicles restricted to the intestinal wall (or absent ?). 



P. ceratodes sp. n. 



About twice as long as broad, laterally flattened, attached by greater 

 part of left side; up to 7 cm. in length, 3.2 cm. in width, and 1.5 cm. in 

 thickness. Apertures sessile or on short siphons; oral 6- or 7- lobed, 

 terminal; atrial 5- or 6-lobed, placed about half the length of the body 

 back along the dorsal edge. Surface irregularly wrinkled and minutely 

 roughened. Musculature practically confined to right side. 



From 50 to 150 tentacles. Prebranchial zone smooth. Aperture 

 of dorsal tubercle horseshoe-shaped, horns incoiled, with one turn in 

 each coil; opening between horns directed forwards. Ganglion from 3 

 to 7 mm. behind tubercle. Dorsal lamina ribbed on left side, its margin 

 finely toothed ; from 2 to 5 teeth between successive teeth corresponding 



