1^07] Bitter. — California Coast Ascidians. 17 



biMiichiiil orifice close to the insertion of the peduncle and dorsal 

 to this, much smaller than atrial, slightly elliptical, elongate 

 crosswise of body, with a low but definite and even lip. Atrial 

 orifice very large and wide open, distinctly elliptical, elongation 

 crosswise of the body, the ventral border somewhat more arched 

 than the dorsal ; edge of the test bordering the opening so even 

 as to give the impression that the orifice has been cut with a die. 

 Tentacles of unequal sizes very long and strong, but branches 

 neither numerous nor large. Branchial membrane without stig- 

 mata, composed of very loose wide-meshed netting of blood ves- 

 sels, the whole so crumpled and distorted in specimens available 

 as to make the true structure impossible of determination. A 

 few spicuj.es, mostly unbranehed, in branchial vessels ; more 

 spicules, these irregularly branched, in tentacles. None of the 

 spicules calcareous, they giving no evolution of gas when treated 

 with acids. 



Digestive Tract. — On left side, stomach not clearly set off 

 from intestine, thin walled, and not ( ?) provided with coeca. 

 Intestinal loop simple, narrow, irregular, the two limbs close to- 

 gether, the rectal being ventral to the stomach and running 

 nearly parallel with and close to the endostyle for some distance. 

 Gonads not determined. 



There is not sufficient material in the collection to enable me 

 to adequately describe this species. Enough can, however, be 

 made out to warrant the conclusion that it is unidentifiable with 

 any Culeolus hitherto described. The external characters, upon 

 which I have chiefly to rely, which appear to differentiate the 

 species, are : the position of the papillary band with reference to 

 the atrial orifice. In most other species possessing the band it is 

 continuous around the orifice instead of, as here, being inter- 

 rupted by it (pi. 2, fig. 21). C. quadrula Sluiter 1904 approxi- 

 nuites C. pyramielalis in this particular more closely, perhaps, 

 than does any other species, but quadrula appears to be without 

 the tuft of larger papillae at the lateral ends of the atrial open- 

 ing, and the especially prominent patch at the ventro-posterior 

 angle or prominence of the body. Furthermore the surface of 

 the test of pyramidulis is not laid off into any such quadrangular 

 areas as is that of quadrula. The radiating plicae and shallow 



