CABEREA 379 



The specimens from Swain's Bay, Kerguelen (99.7.1.846, 851, 853), recorded by 

 Busk (1879, P- io 4) as C- boryi, are a little less robust than those from St. 148, the frontal 

 avicularia are less enlarged, and two outer distal spines are more commonly present. 

 The Challenger material from Marion Island (87. 12.9. 134, 135, 139, 141,99.7.1.852, 

 854) and one specimen from Challenger St. 142 (99.7. 1 .850) x resemble those from 

 Swain's Bay (Fig. 22 C). The specimen from St. 142 has particularly large frontal 

 avicularia on the fertile zooecia. 



The Challenger specimens from Kerguelen (87. 12.9. 137, 142, Challenger St. 149) 

 are exceptionally slender. The branches are not keeled, the frontal avicularia are not 

 enlarged, and the vibracula are not quite so large as those of the colony from Possession 

 Island. Two outer distal spines are usual. 



The Challenger colonies from Nightingale Island, Tristan da Cunha (87. 12.9. 133, 

 99.7.1.847, 849) are intermediate in character between those from Swain's Bay and 

 those of the minima type, the branches being of medium length and only slightly keeled 

 and the outer distal spines usually numbering two and sometimes three (Fig. 22 B). 

 The vibracula are a little smaller than those of the Swain's Bay specimens, and many of 

 the frontal avicularia are enlarged. The figures of these specimens given by Waters 

 (1897, pi. i, figs. 13, 25) are inaccurate, particularly in the relationship of the scutum 

 and the orifice, features in which the specimens agree with those from Swain's Bay. 



The specimens obtained by the National Antarctic Expedition at their winter quarters 

 in McMurdo Sound, Ross Sea, are all of Antarctic type, but some of those taken by the 

 'Terra Nova' in the Ross Sea region somewhat approach the Swain's Bay type. 



In the Discovery collection the majority of the specimens can be put without 

 hesitation into one of three groups {minima type, robust Antarctic type, and inter- 

 mediate Swain's Bay type) described above. The specimens that cannot readily be 

 placed form two groups, one intermediate between the minima and Swain's Bay types, 

 the other between the Swain's Bay and Antarctic types. 



Synonymy. In view of the ease with which the condyle-like process near the base 

 of the operculum (see p. 365 above) can be overlooked, and considering their locality and 

 their agreement with C. darwinii in other respects, I accept Hasenbank's figures of 

 specimens from Bouvet Island as representing C. darwinii. The zooecium in Fig. A 

 is as large as those of Antarctic type, but in other respects (e.g. spines and frontal 

 avicularia) is of less extreme character. Fig. F approaches the minima type, but re- 

 sembles C. glabra (see p. 381) in the shape of the scutum as well as in the absence of the 

 condyle-like process. The zooecium is, however, larger. 



Marcus (1921 a) mentioned that the material from Juan Fernandez was of the strongly 

 calcified type, with short, broad zooecia, which he regarded as the aged state of 

 C. darwinii. I have shown above (p. 374) that his specimens of this type from both Juan 

 Fernandez and Auckland, New Zealand, belong to C. zelandica. His unmounted 

 material from Carnley Harbour, Auckland Island, 6.12.1914 (Marcus, 19216, p. 91), 

 kindly lent me by the Copenhagen Museum, agrees with typical C. darwinii {minima 



1 The other specimens from this station belong to var. occlusa, see p. 385 



