462 University of California Publications in Zoology [Vol.16 



Digestive system. — Situated on left side and posterior end of 

 branchial sac. Stomach longer than broad, and tapering toward 

 esophageal end, its long axis being horizontal and its lower edge about 

 even with lower edge of sac ; its wall thrown into seven distinct 

 longitiidinal folds; a tubular caeciun attached to stomach near its 

 posterior end and upper side (c, pi. 40, fig. 22). Intestine tapers 

 from stomach and almost immediately makes a shaii^ bend and runs 

 dorsally parallel to and above stomach ; upon reaching dorsal edge of 

 body, it turns anteriorly for a short distance; anus situated in lower 

 part of atrial ehainber. 



Reproductive system. — No reproductive organs were seen in the 

 colonies investigated. The fact that the specimens were collected in 

 January and December may account for this. Very young zooids had 

 two great protruding buds, one on each side. In young zooids the 

 atrial orifice is similar to the branchial but takes on the spout-like 

 character as the animal matures. 



Habitat and distribution. — So far as known, B. tuberatus is con- 

 fined to the coast of southern California. No Botryllid has yet been 

 seen north of Point Conception. The type locality of this species is 

 Santa Barbara, and the specimens taken there were on the leaves of 

 kelp, Macrocystis pyrifera. Despite much search in the kelp beds off 

 San Diego, the animal has not been found there. At La Jolla the 

 species occurs in considerable abundance at times on rocks at extreme 

 low tide. This difference in habitat and the fact that the San Diego 

 specimens are, at least in some cases, much more deeply pigmented 

 than those from Santa Barbara and usually devoid of the peculiar 

 tube-lil?e masses of ectodermal ampullae, have caused us to hesitate 

 much as to the propriety of regarding them as belonging to the .same 

 species. However, the absence of differences in the zooids of the 

 colonies from the two localities, the well-lmown color variation in the 

 genus, and the presence of small and somewhat protruding clusters of 

 ampullae on a few specimens from points midway between Santa 

 Barbara and San Diego have led us to follow the more conservative 

 course and treat all the specimens as of the same species. Should 

 future study prove this to be unjustifiable, the San Diego form 

 should be the basis for another species. 



The great pedunculated mas.ses of ampullae are sufficient in tliem- 

 selves to set tuberatus off sharply from the other species of the genus. 



Botrylloides diegensis, n. sp. 



PI. 43, figs. 46^9 



Superfieial characteristics of the colony. — Flat, inerusting. irregu- 

 lar in outline; may be several centimeters in expanse with a thickness 

 of 5 mm. Color in life varying from pinkish yellow to purple. 

 Systems elongated ; number of zooids in a sy.stem variable, ten to 

 fifteen occurring in the older .systems; islands of test ((. t.. pi. 43, fig. 

 49) in the colony surrounded by zooids give impression of systems; 

 atrial orifices not found. Ectodermal vessels and ampullae numerous 

 near margins of colony an'd in island of test ; ampullae oval, and black 

 from accumulation of pigmented cells. 



