1907] Ritter. — California Coast Ascidians. 23 



consequence of such an environment. This does not always seem 

 to be the case. In fact the sacs of two of the species coming from 

 the greatest depths of all are if anything rather stronger than 

 the average. Concerning S. hythia, which was dredged by the 

 Challenger in 2,600 fathoms, Herdman remarks that the branch- 

 ial sac "looks rather thick and opaque," and that this is due to 

 the "large number of internal longitudinal bars present," Herd- 

 man '82. p. 152. The sac of *S'. miUeri may likewise be said to be 

 rather thick and opaque for a Styela, and from the same cir- 

 cumstance. 



A single specimen, station 4396, Long. 33° 01' N., Lat. 121° 

 32' W., :\rarch 31, 1904, 2,228 fathoms, bottom red mud. 



Styela gibbsii Stimp. 



Two specimens of this species were obtained at station 4558, 

 and four at station 4431. The largest of these is 16 mm. long, 

 and all the others, excepting one which is obviously young, are 

 but little smaller. Since these come from two localities and are 

 so nearly uniform in size they may be taken as fully grown. The 

 average length of a hundred or more specimens from Puget 

 Sound, now before me, is 35 or 40 mm., these likewise being quite 

 uniform in size. 



As the species has not been found in Alaskan waters, nor in 

 any abundance on the Southern California coast, it is justifiable 

 to assume that Puget Sound is near its metropolis, and that 

 Southern California is near the southern limit of its range. At 

 Puget Sound it lives in abundance on shore rocks above low- 

 water mark. 



Station 4431, Brockway Point, Santa Rosa Island, S. 43° W., 

 5.2 miles, April 15, 1904, 41 fathoms, yellow mud bottom. Sta- 

 tion 4558. Point Lobos Light, S. 79° W., 2 miles, June 9, 1904. 

 40 fathoms, rock bottom. 



Benthascidia, n. gen. 

 Long pedunculate; no si})hons and no lobes to the apertures: 

 the branchial orifice very large and not closable. Tentacles 

 simple, short, very numerous, and many short papillae on the 

 inner surface of the intratentacular cii-clet. Branchial membrane 

 very delicate and ivifhotif true stigmata. 



