NOTES 281 



Two rare Corals, and Polyzoa from Rockall. — Whilst 

 fishing in deep water off Rockall, between 13th and 19th October 

 1 91 2, an Aberdeen fishing-boat caught upon its lines two fine 

 colonies of Coral, which were landed in good condition. 



A large creamy-white colony, 21.5 cm. high and 10 cm. 

 across, represents the rare British Tuft-Coral, Lophohelia prolifera 

 (Pallas), a representative of the Madrepore or Reef-Corals. The 

 species has been found in deep water off Skye, and one enormous 

 example, 6 lbs. in weight, was found between Rum and Eigg, and 

 perhaps exists, as an unlabelled specimen, in the Natural History 

 Museum at Marischal College, Aberdeen. The "Porcupine" 

 obtained examples from the south and south-west of Ireland, and 

 from the same area many colonies have recently been dredged by 

 the Irish Fisheries Investigation, at depths from 215 to 800 fathoms. 

 Besides occurring dispersed over the North Atlantic Ocean, the Tuft- 

 Coral has been found in the South Atlantic and Indian Oceans. 



The second colony is a Hydrozoan Coral belonging to the order 

 Stylasterina. It is creamy-yellow in colour, with traces of pinkish 

 patches, and is a complete and well-developed example of Sty/aster 

 gemmascens, M. Edw. and Haimc. The colony is 10 cm. high and 

 9.5 cm. broad, with base widespread and massive, supporting a 

 stem 12 mm. in diameter, which divides into two main branches, 

 7 mm. in diameter. The polyp systems (cyclostems) are very wide, 

 sometimes 2 mm. across, and are notched to hold fourteen to 

 sixteen protective individuals (dactylozooids). Sty/aster gemmascens^ 

 described originally from the Indian Ocean, was found in the North 

 Atlantic at a depth of 530 fathoms by the "Lightning" and 

 "Porcupine." It has been recorded from great depths in the 

 Foldenfjord, Norway, by G. O. Sars (1872), and Prof. Hickson 

 and Miss England have examined specimens from the Sulu Sea, 

 East Indies (1905). That it is not uncommon off Rockall is 

 indicated by the fact that an example from this neighbourhood has 

 already been recorded, by Prof. J. Arthur Thomson, in Proc. Roy. 

 P/iys. Soc, vol. xviii., 19 10, p. 61. 



In company with the Corals, from the same area, was a colony, 

 with spread of 10 cm., of the coral-like Polyzoon, Pore I la compress a 

 (Sowerby), and on it were growing two examples of encrusting 

 Polyzoa— Membranipora catemilaria (Jameson), and Lichenopora 

 hispida (Fleming). 



The Rockall Corals are now to be seen in the British Hall of 

 the Royal Scottish Museum. — James Ritchie. 



12 2 N 



