4§ DISCOVERY REPORTS 



C. spiralis, Karsten, was recorded in small numbers at a single station : WS 34. 



C. sub-bulliens, Jorgensen?. The specimens which we have queried under this name 

 appear to agree with those of this species from the northern hemisphere except that 

 they lack the two small apicules. They were taken on the western side of South Georgia 

 in January and on the eastern side in late May 1927. Their numbers and distribution 

 are shown in Appendix I. 



Forms very similar to C. sub-bulliens, but lacking the spinulae as well as the two 

 apicules, were noted and recorded amongst those unidentified. 



C. subtilis, Ehr.: one specimen was recorded at St. 160. 



C. stellaris, Roper: two specimens were recorded at WS 112. 



Under Coscinodiscus spp. have been included examples of a diatom which bears a very 

 close resemblance to C. stellaris, save that it has not the characteristic stellate marking 

 of the species. These forms were taken in small numbers at the following stations as 

 follows: WS 35, WS 36, WS 37, WS 39, WS 43 and WS 45. 



Forms closely resembling C. quinquies-marcatus both in the sculpturing of the valves 

 and their concave surfaces but lacking the apicules, were recorded at Sts. 160, WS 44, 

 WS 45, WS 51, WS 63 and WS 70. 



Other examples of the genus which were not specifically identified were taken as 

 follows: WS 33, 200(1); WS 41, 180(3); WS 61, 100(1); WS63, 1200(4); WS no, 

 200(1); WS 1 1 1, 600 (2); WS 112, 24,400 (244); WS 1 13, 2ooo(io);WS 1 14, 27,000(270). 



Actinoptychus. 



The two species recorded have only been taken in very small numbers: A. undidatus, 

 Bail., at WS 63, WS noandWS in, and A. vidgaris, Schum., at St. 125 and WS 112. 



Asteromphalus. 



Five different species were not infrequently met with, but only occurred in small 

 numbers. The commonest were A. brookei, Bail., A. hookeri, Ehr., and A. regularis, 

 Karsten: their distribution and numbers are shown in Appendix I. 



A. challengerensis, Castr., occurred at the following stations: 133, 137, 138, WS 33, 

 WS 34, WS 35, WS 36, WS 37 and WS 113. 



A.parvulus, Karsten, at Sts. 137, 160, 161, WS 35, WS 40 and WS 45. 



There also occurred forms which we have indicated as Asteromphalus sp., which was 

 similar to A. challenger ensis but with nine rays instead of eight; these occurred at 

 Sts. 133, 134, 137, WS 33, WS 35 and WS 36. We are inclined to regard them as 

 varieties of A. challenger ensis; they occurred in six out of seven instances at stations 

 at which A. challengerensis also occurred and in the seventh in close proximity to such 

 stations. Still more significant, at St. 137 we found a form which was 8-rayed in one 

 valve and 9-rayed in the other. A. challengerensis and the 9-rayed forms were all con- 

 fined to water of Weddell Sea origin. 

 Actinocyclus antarcticus, Karsten. 



This species was found only in very small numbers at the following stations: WS 34, 

 WS 38, WS 67 and WS no. 



