448 University of California Publications in Zoology [Vol.16 



Halocynthia johnsoni Ritt. 



Hatocynthia johnsoni, Ritter, 1909. 



A striking thing about this species is its great abundance in San 

 Diego Bay, and the large size reached there by the individuals, as 

 compared with what one finds on the open shores. Its favorite habitat 

 appears to be the piles of wharfs where, at times, it makes almost a 

 solid coating. Although it must be counted as a native of the whole 

 littoral zone, we have found onl_v occasional small specimens at outside 

 points. 



Mention may be made of the fact that before San Pedro Bay was 

 completely dredged to make it a harbor, H. johnsoni occurred there 

 in the shoaler waters in enormous numbers on the bottom, associated 

 with several species of lamellibranch molluscs. 



Styelamontereyensis (Dall) 



PI. 38, fig. 1; pi. 41, fig. 28-34 



CyntMa( ?) montereyensis, Dall, 1871, p. 157. 



Clavelinopsis rubra, Fewkes, 1889. 



BoUeniaf?) rubra, Herdraan, 1891, p. 599. 



Styela montereyensis, Ritter, 1893, p. 39. 



Styela montereyensis, Bancroft, 1899, pp. 73 and 92. 



Styela (sens, restr.) montereyensis. Huntsman, 1911, p. 131. 



Although styela montereyensis was, so far as we know, the first 

 ascidian ever described from the California coast, and though it has 

 been studied more, probably, than any other, because of the meager- 

 ness of the original description we describe it as fully as though it 

 were a new species. 



Superficial characteristics (pi. 38, fig. 1). — Long, club-shaped, 

 pedunculated ; prevailing color dark red. Peduncle at least as long as 

 body, often twice as long. Test firm, thick, opaque, with about twelve 

 corrugations. Transverse wrinkles often occur, particularly at anterior 

 end and along peduncle. Both orifices 4-lobed ; siphons always distinct, 

 the branchial being directed ventrally with a pronounced uniform 

 curve, the atrial directed anteriorly. Body merges gradually into 

 peduncle. IMantle fairly mu.seular but semitran.sparent, containing 

 two layers of muscle, an inner one of longitudinal bands overlaid by 

 a more delicate layer of transverse fibers crossing it at right angles; 

 both layers become feeble posteriorly and wholly disappear in the 

 peduncle. 



Table 1 gives measurements for Styela mo)itereyensis from different 

 localities. 



