238 



DISCOVERY REPORTS 



St. 39. 25. iii. 26. West Cumberland Bay, South Georgia, 179-235 m. 4 specimens. 

 St. 123. 15. xii. 26. Off mouth of Cumberland Bay, South Georgia, 230-250 m. 2 specimens. 

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



St. 140. 

 mens. 

 St. 144. 

 St. 148. 

 St. 170. 



5. i. 27. Off mouth of Stromness Harbour, South Geotgia, 155-178 m. 

 9. i. 27. Off Cape Saunders, South Georgia, 132-148 m. i specimen. 

 23. ii. 27. Off Cape Bowles, Clarence Island, 342 m. i specimen. 



4 specimens. 



Most of the larger specimens of this species are carrying a smaller one on their back 

 (Plate VII, fig. 8), a fact naturally leading to the suggestion that this is a sort of copula- 

 tion, the larger specimen being the female, the smaller the male. And so it actually 

 is, as proved by the examination of the gonads of these specimens. It was possible also 

 to demonstrate that the species is viviparous. The two first specimens opened had their 

 bursae entirely empty ; the third had them packed with eggs, which seemed, however, 

 to be only just fertilized. But the fourth specimen opened settled the question, for it 

 had the bursae filled with embryos, all in the same stage of development. The embryos 



a A^)^ 



Fig. 2a-c. Astrochlamys bruneus, Koehler. a. Part of oral side, xS. b, Embryo, showing the five 

 terminal plates, and in the centre the mouth, x8o. c, Arm spine, X45. 



Fig. 2 d. Arm spine of Astrochlamys sol, n.sp., X45. 



were small and star-shaped, with an indication of a mouth invagination and the first 

 indication of the skeleton, viz. the terminal plate ; but as yet there was no trace of the 

 ambulacral skeleton or of any other plates (Fig. 2 b). There were some 200 embryos in 

 each bursa, which means that they cannot reach any large size before they leave the 

 mother — in conformity with the small size of the genital slits. The eggs are shed (into 

 the bursae) all at a time, and this appears to be likewise the case with the sperms, none 

 of the males being found to contain ripe sperms in their gonads. This is again in con- 

 formity with the fact that some of the larger specimens carry no male on their back, so 

 that copulation is not going on constantly, as is the case in Amphilycus androphorus, 

 Mortensen, and, to a less degree apparently in Ophiosphaera insignis, Brock, and 

 Ophiodaphne materna, Koehler (cf. Mortensen, Biological observations on Ophiurids. 

 Papers from DrTh. Mortensen's Pacific Exped., LXiii (Vid. Medd. Dansk Naturh. Foren., 

 93), 1933, pp. 178-88). In these three Ophiurids the male is carried over the mouth of 



