191 1] ASCIDIANS FROM THE COASTS OF CANADA. 1 19 



Family — Cionidae. 

 Ciona intestinalis (L.) 



Specimens were taken frequently in and near Departure Bay, but 

 never in quantity. They seem to dififer from European specimens only 

 in the small number (5) of muscular bands on each side of the body. 

 To judge from the published figures, the number is variable in European 

 specimens (6 or 7). 



Family — Phallusiidae. 

 Genus — Ascidiopsis Verrill {sens. nov.). {=Ascidia seu Phallusia 

 auct. partim). 



The type species is Ascidia callosa Stimpson {=A. prunum Miiller). 

 Verrill instituted this genus for the type because of the plicated condi- 

 tion of the pharyngeal wall. This is a character common among Phal- 

 lusiids and one that cannot be used as a distinctive feature. The diag- 

 nosis may be changed so as to include those forms with the pharynx ex- 

 tending beyond oesophageal aperture but not beyond the posterior side 

 of the stomach, longitudinal bars bearing papillae and intermediate 

 papillae, and renal vesicles occurring over intestinal loop and in the ad- 

 jacent parts of the body-wall. Also the ganglion is close to the dorsal 

 tubercle. This genus is intermediate between Ascidiella (as restricted 

 by Hartmeyer) and the typical Phallusiae (e.g. P. mentula). 



A. nanaimoensis sp. n. 



Oblong, laterally flattened; attached by left side. Up to 27 mm. 

 in length. Oral aperture terminal, 7- (or 5-) lobed; atrial, distant from 

 oral from one-third to one-half the length of the body, 6- lobed. Surface 

 nearly smooth (minute papillae over part of surface). Musculature 

 practically confined to right side of body. 



From 45 to 105 tentacles. Prebranchial zone with indistinct pa- 

 pillae. Aperture of dorsal tubercle crescent-shaped, opening between 

 horns directed forwards. Ganglion is the width of peripharyngeal groove 

 behind tubercle. Dorsal lamina prominently ribbed, its margin with 

 coarse teeth corresponding to the ribs. Longitudinal bars, from 41 to 

 50 on the left side and from 48 to 66 on the right. Plications fewer than 

 the bars. From 3 to 6 stigmata in each mesh. 



Stomach with 17 shallow folds; intestine without typhlosole. Ovary 

 in intestinal loop and on right side of first part of intestine. Testicular 

 lobes in intestinal loop posteriorly, on both sides of first part of intestine 

 and on right side of stomach. Gonoducts pass along posterior side of 

 last bend of intestine. 



Three specimens obtained at points near Departure Bay. 



This species somewhat resembles in appearance Ascidia adharens 



