328 DISCOVERY REPORTS 



season. Specimens of the same species dredged at different times of the year show 

 uniformity in the number of buds produced and this fact may be sufficient evidence to 

 show that buds are produced all the year round. Living as they do in the cold waters 

 of the Antarctic Seas, where submarine conditions are similar throughout the year, it 

 is not to be expected that the seasons could have much influence on budding. We might 

 expect to find indications of seasonal changes on the forms from shallower waters such 

 as C. indiciis from the coast of Ceylon, C. levinseni from the coast of Japan or C. gilchristi 

 from the South African coast, where the changes are very marked; but reports on these 

 do not mention what influence seasons have on budding. The presence or absence of 

 end-bulbs on the arms, and sometimes (e.g. C. nigrescens and C.foimosus) the presence 

 of dark lines along the axes of the arms are also characters which help identification. 



Sub-genus Demiothecia 



Cephalodiscus hodgsoni, Ridewood. (PI. XXXIII, figs. 1-5.) 



C. hodgsoni, Ridewood, 1907 b. 

 C. inaequatus (Andersson), 1907. 



Diagnosis. Irregularly branched colony without cross bars between branches. Width 

 of branch excluding spines usually 4 to 6 mm. ; some basal stems 9 mm. Cavity of 

 coenoecium continuous, the smooth inner lining sometimes traversed by solid bars. 

 Zooids and buds occupy the cavity in common. Older parts of the coenoecium deep 

 amber colour. Ostia numerous, irregularly placed, funnel-shaped and each with two to 

 five simple or forked spines. Zooids: length of a fairly extended zooid from free end of 

 arms to end of body 2 to 3-2 mm. Colour of preserved zooids, reddish or pale brown. 

 Arms, five or six pairs. Axes of each arm have an end-swelling, with refractive beads. 

 Male and female zooids and hermaphrodites occur in the same colony. Buds, two, 

 three or four to each zooid. 



Material. The material of C. hodgsoni was obtained from the following stations: 



St. 167. 20. ii. 27. Off Signy Island, South Orkneys, 60° 50' 30" S, 46° 15' 00" W. Gear OTL. 

 244-344 m. One specimen. 



St. 187. 18. iii. 27. Neuinayr Channel, Palmer Archipelago, 64° 48' 30" S, 63° 31' 30" W. Gear 

 DLH. 259 m. One specimen. 



St. 190. 24. iii. 27. Bismarck Strait, Palmer Archipelago, 64° 56' 00" S, 65° 35' 00" W. Gear 

 DLH and NRL. 93-126 m. Twelve specimens. 



St. WS18. 26. xi. 26. 54° 07' 00" S, 36° 23' 00" W. Gear OTL. 160-330 m. Small fragment. 



Stations 167 and 187 yielded only two small pieces of dead colonies. Inhabited 

 colonies, dredged from station 190, consisted of twelve fragments, which were labelled 

 in two bottles, owing to differences in the spines. The dimensions of entire colonies 

 given by Ridewood (1907 b, p. 50), show that these are only broken bits of large colonies. 

 The basal attachment is found in only one possibly entire colony. 



The difference between two distinct types of colonies obtained from station 190 is 

 shown in PI. XXXIII, figs, i and 2. Careful study of their structure shows that the 

 thickness of the coenoecium, the number of spines and the short branches on the colony 



