596 CLAVELLINID^. 



Genus PEROPHORA, Wiegmann. 



Individuals pedunculated, sub- orbicular, compressed, at- 

 tached by their peduncles to creeping tubular processes of 

 the common tunic, through which the blood circulates; 

 thoracic region plain, not lineated by granular bands. 



Ex. P. Listeri, Wiegman, pi. 133, fig. 8. 



The only species of Perophora known inhabits the Bri- 

 tish coasts. It occurs in groups consisting of several indi- 

 viduals, each having its own heart, respiration, and system 

 of nutrition, but fixed on a peduncle that branches from a 

 common creeping stem, and all being connected by a circu- 

 lation that extends throughout (Lister). 



Genus SYNTETHYS, Forbes and Goodsir. 



Animals compound, gelatinous, orbicular, sessile. Indi- 

 viduals very prominent, arranged sub-concentrically in the 

 common mass; branchial and anal orifices simple, not cut 

 into rays. 



Ex. S. Hebridicus, Forbes and Goodsir, pi. 133, fig. 9. 

 Individual, S. Hebridicus, fig. 9, a. 



Syntethys is a Glavellina with the habit of a Diazona. 

 The only known species forms compact, greenish, translu- 

 cent, gelatinous masses of half a foot in diameter and nearlv 

 equal height, affixed to rocks or stones by a short base. 

 The individual Ascidians are, when full grown, two inches 

 in length (Forbes). 



