CIDARIDAE 209 



ECHINOIDEA 



Family CIDARIDAE 



Ctenocidaris speciosa, Mortensen 



(Plate I, figs. 2-12) 



Ctenocidaris speciosa, Mortensen, 1910. Swedish South Polar Exped. Echinoidea, vi, 4, p. 4, 



pis. i, ii ; iii, figs. 1-2 ; iv, figs. 1-3 ; xiii. 

 C. speciosa, H. L. Clark, 1925. Cat. Recent Sea-Urchins Brit. Mus., p. 36. 

 C. speciosa, Mortensen, 1928. Monogr. Echinoidea. I, Cidaridae, p. 122. 



St. 27.1 15. iii. 26. West Cumberland Bay, South Georgia, iiom. Some young specimens, 

 infested with Echitiophyces mirabilis, Mortensen. 



St. 39. 15. iii. 26. East Cumberland Bay, South Georgia, 179-235 m. i specimen. 



St. 42. I. iv. 26. Off mouth of Cumberland Bay, South Georgia, 120-204 m. Several specimens, 

 some of them very young ; partly infested with Echinophyces. 



St. 123. 15. xii. 26. Off mouth of Cumberland Bay, South Georgia, 230-250 m. 5 specimens, 

 3 of them infested with Echinophyces. Also 4 very young specimens, just liberated from the 

 marsupium. 



St. 140. 23. xii. 26. Stromness Harbour to Larsen Point, South Georgia, 122-136 m. 3 small 

 specimens, infested with Echinophyces. Also some very young specimens. 



St. 142. 30. xii. 26. East Cumberland Bay, South Georgia, 88-273 ™- ^ specimen. 



St. 144. 5.1.27. Off mouth of Stromness Harbour, South Georgia, 155-178 m. 3 specimens. 



St. 148. 9. i. 27. Off Cape Saunders, South Georgia, 132-148 m. 6 specimens. 



St. 160. 7. ii. 27. Near Shag Rocks, South Georgia, 177 m. i large, fine specimen and some 

 small ones. 



St. 170. 23. ii. 27. Off Cape Bowles, Clarence Island, 61° 25' S, 53° 46' W, 342 m. i specimen. 



St. 190. 24. iii. 27. Bismarck Strait, Palmer Archipelago, 64° 56' S, 65° 35' W, 308-315 m. 

 6 specimens. 



St. 600. 17. i. 31. 67° 09' S, 69° 27' W, off Adelaide Island, 487-512 m. i damaged specimen: 

 identification not quite certain. 



St. WS 33. 21. xii. 26. 54° 59' S, 35° 24' W, 135 m. 2 specimens. 



St. WS 42. 7. i. 27. 54° 41' S, 35° 47' W, 175 m. 2 specimens. 



St. MS 71. 9. iii. 27. East Cumberland Bay, South Georgia, 110-60 m. 5 specimens. 



This species evidently is quite common off South Georgia and the Shag Rocks, whence 

 the type specimens were brought home by the Swedish South Polar Expedition. As 

 with the original specimens, some of those taken by the Discovery Expedition have the 

 primary spines much overgrown with the slimy colonies of the Bryozoan Alcyonidium 

 (Plate I, fig. 5), other specimens having them covered by great numbers of a small white, 

 viviparous bivalve Mollusc {Limopsis sp.) (Plate I, figs. 2, 4). Adult specimens with the 

 primary spines clean, not occupied by these -commensals, are only rarely found. 



A considerable percentage of the smaller specimens are of a quite peculiar appear- 

 ance. The primary spines are more distinctly thorny and more slender than normal, and 



* Further data concerning the stations where specimens were taken, including the nature of the 

 bottom, the gear used and the temperature and saUnity of the water, will be found in the Station 

 Lists issued in this series of Reports. Particulars of Sts. 1-700 and Sts. WS 1-575 have already been 

 published, and other lists dealing with later stations will appear in due course. 



