W. G. Van Name — Bermuda Ascidians. 373 



state), and pale yellowish in color. The mantle is not noticeably 

 muscular, but there are strong muscles on the transverse vessels of 

 the branchial sac and along each side of the dorsal lamina. 



There are four rows of a dozen or moi'e rather long stigmata and 

 apparently about a dozen tentacles. Between the thorax and abdo- 

 men the body is constricted into a narrow but rather short 

 peduncle. The mantle is somewhat produced just anterior to the 

 atrial orifice, but hardly sufficiently to be termed a languet. The 

 branchial siphon is short and has six small lobes. 



The intestine forms a rather small twisted loop, and the stomach 

 is rounded and smooth-walled externally, though slightly ridged on 

 the inner surface in a longitudinal direction. 



Though I have examined a great number of the zooids, I have not 

 found any with sexual organs developed, but many of them have 

 small buds in the region of the peduncle. 



Three small colonies were found in 1898, one of which was grow- 

 ing on a specimen of Clavelina oblong a / the other two on a 

 branching alga. None were collected in 1901. I do not know the 

 exact locality where the specimens were obtained. 



Family BOTBYLLIDiE Verrill, 1871. 



Colony thin and expanded or thick and fleshy. Zooids always 

 arranged in systems. Test gelatinous, traversed by branching ves- 

 sels with enlarged terminal bulbs, which are especially numerous 

 near the margins of the colony. 



Zooids short-bodied, not divided into thorax and abdomen. 



Branchial sac large, with numerous stigmata and with several 

 internal longitudinal bars on each side, but no folds. Dorsal lamina 

 a plain membrane. Tentacles usually few. 



Loop of alimentary canal placed alongside the posterior portion 

 of the branchial sac. Stomach-wall folded longitudinally. A large 

 gastric coecum is present. 



Reproductive organs (both ovaries and testes) developed on both 

 sides of the body. Budding from wall of peribranchial cavity. 



ISymplegma Herdman presents exceptions to this diagnosis. 



Genus Botrylloides Milne-Edwards, 1842. 



Distinguished from Botryllus by having the zooids arranged in 

 extended branching systems instead of small round or oval ones, and 

 from Sarcobotrylloides von Drasche by forming thin instead of 

 thick fleshy colonies. 



