DESCRIPTION OF SPECIES 91 



Dorsal tubercle. In one of the specimens examined, the dorsal tubercle is of a simple U -shape, 

 with the right limb a little turned inwards (Text-fig. 28 C). In another specimen the opening is 

 broken up into a number of irregular pieces, but is still basically U-shaped (Text-fig. 28 D). 



Branchial sac. There are fifty to sixty longitudinal bars on each side of the branchial sac. 



Gut. The gut (Fig. 28 B) is very like that illustrated by van Name (1945, fig. 97). 



Gonads. In all three specimens the testis is poorly developed, and the ovary is a small slightly 

 lobed body lying within the intestinal loop (Text-fig. 28 B, ov.). 



20cm 



Text-fig. 28. Ascidia interrupta Heller (St. 279): A, external appearance; B, specimen with test removed; 



C, D, dorsal tubercles of two specimens. 



Remarks. These animals from the French Congo, West Africa agree very closely with the detailed 

 description given by van Name (1945) of the species as it occurs on the tropical coasts of the American 

 side of the Atlantic. So far as I am aware, it has not been recorded hitherto from the African coast 

 and the ' Discovery ' specimens are from deeper water than previous records. This is a further example 

 of the distribution of a tropical species on both sides of the Atlantic. 



Distribution. East coast of tropical America; French Congo, West Africa. 



Ascidia sydneiensis Stimpson (Text-fig. 29) 



Ascidia sydneiensis Stimpson 1855, p. 387. 

 For synonymy see van Name 1945. p. 189. 



Occurrence. St. 90: False Bay, S. Africa, 0-2 m. St. 1686: Victoria, Australia, o m. 



External appearance. The specimen from False Bay, South Africa is 5-0 cm. long and 3-0 cm. 

 wide. The specimen from Victoria, Australia is 9-2 cm. long and 6-9 cm. wide. 



Internal structure. Both specimens are quite typical of this species. Each shows the charac- 

 teristic bands of muscles on the right side (Text-fig. 29 B), the large number of oral tentacles (150-200), 

 and the complex dorsal tubercle. 



Remarks. In the South African individual the gut is full of food, consisting largely of algal cells, 

 diatoms and peridineans with a certain amount of coarser inorganic matter. 



Distribution. Widely distributed throughout the warmer and temperate waters of the world. 



