126 DISCOVERY REPORTS 



Gut. A number of branched hepatic lobes are given off from the surface of the stomach (st .) but 

 as they are few, most of the stomach is exposed. The primary loop of the gut is rather widely open. 

 Kott (1952) has described the anal border in this species as 'smooth ' in her Australian specimens, and 

 as 'gently indented, but not divided into distinct lobes', in a later publication (Kott, 1954) dealing 

 with material from Macquarie Island, Kerguelen and Tasmania. The 'Discovery' specimen from 

 Marion Island has the anal border minutely cut into about thirty very short lobes (Text-fig. 51 G). 



Gonads. One curved gonad (g) lies on each side of the body and comprises about twelve pairs of 

 sac-like lobes arranged along the gonoducts. 



Remarks. Apart from the subdivision of the anal border, this specimen is in good agreement with 

 Kott's (1952, 1954) accounts of P. jacatrensis. It appears doubtful, however, whether this species is 

 sufficiently distinct from P. vittata (Stimpson). In her key to the species of Pyura, Kott (1952, 

 pp. 260-3) separates P. jacatrensis from P. vittata by the smooth anal border of the former and the 

 lobed border of the latter. But there are differences in the published descriptions of the anal border in 

 P. vittata. Thus according to van Name (1945) the border is 'usually with rounded lobes', and it is 

 variously described by Tokioka as indistinctly lobed (1949), 'not lobed' (1950) and 'plainly margined' 

 (1952). In spite of the unsatisfactory nature of the distinctions, it is unlikely that the two species are 

 the same, since P. vittata is known chiefly from the tropical and subtropical waters of eastern America 

 and West Africa, and from Japanese waters, whereas P. jacatrensis has been recorded from Indonesia, 

 Western Australia, Tasmania, Kerguelen and Macquarie Island. Further evidence might show that 

 the records from warm waters refer to P. vittata, and those from Kerguelen, Marion Island, Macquarie 

 Island and perhaps Tasmania refer to a different species. But there is not yet enough information to 

 make a decision possible. 



Distribution. Indonesia, Western Australia, Tasmania, Subantarctic (Macquarie Island, Marion 

 Island), Antarctic (Kerguelen). 



Pyura vittata (Stimpson) 



Cynthia vittata Stimpson, 1852, p. 230. 

 For synonymy see van Name, 1945, p. 321. 



Occurrence. St. 1 : Ascension Island, S. Atlantic Ocean, 16-27 m - 



External appearance. The single specimen measures 2-0 by 1-5 cm., has a very irregular outline 

 owing to the presence of rounded swellings on the surface, and is dirty pale grey in colour. 



Internal structure. The specimen was somewhat damaged but all details which were seen are 

 typical of the species, and may be summarized as follows : Tentacles 32. Dorsal tubercle with C-shaped 

 slit having inrolled horns. Thirty slender dorsal languets. Six branchial folds with bars arranged thus : 

 dorsal line 3 (13) 5 (17) 3 (17) 4 (20) 8 (15) 6 (12) 7 endostyle. Stomach with large branched liver. 

 Endocarps along dorsal side of intestine. Gonads not present. The only point needing special mention 

 is the two-lipped anus. This does not agree with van Name's (1945) description of the species as found 

 in tropical American waters, the nearest locality with adequately described specimens. But the 

 apparently variable form of the anal margin (see remarks under P. jacatrensis) shows that it is not an 

 important diagnostic character. 



Distribution. Warm waters of the Atlantic coast of America ; west Africa, Ascension Island, Japan. 



Genus Herdmania Lahille, 1887 



Herdmania momus (Savigny) (Text-fig. 52) 



Cynthia momus Savigny, 1816, p. 143, pi. 1, fig. 2; pi. 4, fig. 1. 



For synonymy see Kott, 1952, p. 279 (var. grandis), p. 281 (var. galei), p. 282 (var. curvata). 



