DESCRIPTION OF SPECIES 87 



The systematic position of the genus has been much discussed. Originally placed in the family 

 Polyclinidae by Herdman (1886), it is now generally regarded as a phlebobranchiate ascidian, related 

 to, or actually within, the family Diazonidae. The larva, with its triangular arrangement of the papillae, 

 also shows that the genus should be removed from the Polyclinidae. 



The ' Discovery ' records are of special interest as they extend the known range northwards to the 

 edge of the Antarctic and beyond into the Subantarctic (Patagonian Shelf). Arnback (1950) had 

 already recorded the species (as T. antarcticum) from South Georgia, at that time the most northern 

 locality. 



Distribution. Antarctic (Cape Adare, MacRobertson Land, Kaiser Wilhelm II Land, Graham 

 Land, South Georgia, South Shetland Islands, South Sandwich Islands), Subantarctic (Patagonian 

 Shelf). 



Family ASCIDIIDAE Adams, 1858 



Genus Ascidia Linnaeus, 1767 



Ascidia translucida Herdman (Text-fig. 26) 



Ascidia translucida Herdman, 1880, p. 466. 

 ? Ascidia plicata Kott, 1954, p. 150, fig. 31. 



Occurrence. St. 39: S. Georgia, 179-235 m. St. WS25: S. Georgia, 18-27 m. St. MS 10: 

 S. Georgia, 26-18 m. St. MS 65: S. Georgia, 39 m. St. MS 68: S. Georgia, 220-247 m - 

 External appearance (Text-fig. 26A). The largest of the six specimens is 19-0 cm. long and the 



Text-fig. 26. Ascidia translucida Herdman (St. MS 68): A, external appearance; B, specimen with test removed; 

 C, D, E, dorsal tubercles of small, medium and large specimens, respectively. 



