l-'i"] Ritter-Forsijth : Ascidiaiis of Southern California 443 



Branchial sac much as in Ascidia, but with a series of languets in jilaee of 

 dorsal lamina. 



Intestine wholly or largely behind the brancial sac. 

 Sexual organs in the intestinal loop. 



Suborder II. ASCIDIAE COMPOSITAE 

 Individuals, called zooids, produced asexually by budding; typically many; 

 small, usually less than 1 cm. long; in most genera connected together by per- 

 manent stolons and embedded iu a common mass of cellulose mantle or test ; 

 but in some genera zooids larger and not fully embedded in the common mass; 

 the wliole group of zooids, produced from a single parent, called a colony. 



Genus 7. Metandrocarpa 



Colony encrusting on rocks, seaweeds, and other objects; zooids never ar- 

 ranged in systems; cellulose mantle tough; color brick-red. 



Form of zooid globular, body not divided into sections. 



Branchial sac without folds but with internal longitudinal vessels; branchial 

 and atrial tentacles present, all simple. 



Intestine short, situated on the left-ventral side of the branchial sac; stomach 

 with a series of folds and a large caecum. 



Sexual glands two series of masses called polycarps, one on each side of the 

 endostyle, each polyearp with its own short duct opening into the perbranchial 

 chamber ; the anterior polycarps of each series female, the posterior male. 



Buddinri thoracic. 



Genus S. Polyzoa 



Like Metandrocarpa except: 



Colony with zooids united only by strands; no common investing cellulose 

 mass; colorless, transparent. 



Sexual glands all hermaphroditic polycarps. 



Genus 9. BotryUus 



Colony thin and encrusting; zooids wholly embedded in common cellulose 

 mass, arranged in regular or somewhat elongated "systems" around a common 

 atrial opening; cellulose mass containing many vessels terminating in ampullae; 

 color various, often very conspicuous. 



Form of zooids generally elliptical, body not divided into sections. 



Branchial sac without folds but with a few internal longitudinal vessels. 



Intestine on left side at posterior end; stomach with folds and a caecum. 



Sexual glands a single pair of hermaphroditic masses, one on each side of a 

 branchial sac. 



Budding thoracic. 



Genus 10. Botrylloides 



Like BotryUus except: 



Colony with zooids arranged in long-elliptical or tortuous systems. 



Genus 11. Perophora 



Colony composed of zooids conected by stolons, partly or wholly embedded in 

 cellulose mass; zooids never in systems; transparent to yellowish white. 



Form of zooids spheroid, body not divided into sections; branchial orifice 

 6-lobed, atrial 5-lobed. 



Branchial sac without folds, with internal longitudinal vessels or papillae; a 

 series of languets along mid-dorsal line. 



