191"] Rifter-Forsijtli: Asridiaiis of Soutlicni California 465 



surface as a delicate-walled short pipe. Color light green, variable, 

 dark brown, cadmium-yellow, brick-red, dirty white. Test consisting 

 of a thin, tongh oxiter layer covering the less resistant inner portion, 

 both having many bladder cells; ectodermal vessels running parallel 

 with long axis of peduncle and not branching or anastomosing. 



Zooids (pi. 45, fig. 6-4). — Small, from 2 to 3 mm., average of twelve 

 individuals 2.5 mm. Mantle delicate, containing many diagonally 

 running muscle fibers; two strong dorsal longitudinal muscle bands 

 extending from the vicinity of branchial siphon to the esophagus, 

 causing branchial sac to shrink along dorsal sides in preserved speci- 

 mens. The atrial languet long, but varying in shape and size depend- 

 ing on position of zooid in colony ; one or three-lobed. 



Branchial system. — Branchial siphon large with six broad blunt 

 lobes. At base of siphon sixteen tentacles, four placed symmetrically 

 at the quadrants of circle, much larger; alternating with these, four 

 about half as long: finally alternating with the eight, eight very short 

 ones (pi. 45, fig. 65). Branchial sac with four series of stigmata; the 

 most posterior series having the longest stigmata, those of the other 

 series gradually shorter in order ; the stigmata long and slender, about 

 twelve in a half-series; each series crossed by a delicate intermediate 

 transverse vessel which does not interrupt stigmata ; in young indi- 

 viduals stigmata become gradually smaller toward endostyle, leaving 

 triangular spaces between series and main transverse vessels. Dorsal 

 languets three, about half the length of the stigmata, located a little 

 to left of mid-dorsal line. 



Digestive system. — Esophagus about equal in length to stomach 

 and very slightly twisted. Stomach inflated in appearance, egg-shaped, 

 long in proportion to its breadth ; smooth on outer surface, slight, dis- 

 continuous, branching ridges generally longitudinal on inner surface, 

 giving it a reticulated appearance ; long axis of stomach forming a 

 slight angle with long axis of zooid. On emerging from stomach, 

 intestine runs ventrally for a distance equal to width of .stomach, then 

 bends anteriorly and maintains a straight cour-se until it ends as a 

 lobed anus near the middle of branchial sac. Ramifying over the 

 intestine from the pylorus halfway up to anus is the pyloric gland 

 (p. gl, pi. 45, fig. 64). Within intestinal loop is a clear bulb which 

 is part of this svstem; this connected with stomach by a fine duct 

 (pi. 45, fig. 64). ' 



Reproductive sy.'^teni. — Testicular lobes and ovary on right side of 

 intestinal loop in young individuals, but in adults ovary always pos- 

 terior to loop and testis largely so. though owing to its great size it may 

 extend beyond the loop in both directions; testicular lobes all com- 

 municating with the vas deferens at one point by delicate va.sa effer- 

 entia; the" vas deferens running along intestine nearly to the anus. 

 Oviduct a thin-walled tube lying immediately over the vas deferens, 

 bending to enter incubatory pouch at right dorsal posterior corner of 

 branchial sac. Incubatory pouch (t. p.. pi. 45, fig. 64) containing Uy 

 or three eggs, very rarely four; larvae present in colonies taken in 

 June and July; absent in colonies taken in January. 



Habitat and di.strihution.— On rocks in littoral zone from San 

 Diesro to Puget Sound, common in many places. 

 Type locality. — San Diego, California. 



