264 DISCOVERY REPORTS 



Oil Hermaphroditism in viviparous Ophiiirids (1920, p. 4), the very numerous small eggs 

 excluding the possibility of viviparity or brood-protection. The examination of the rich 

 material in this collection confirms this statement. No doubt it has a typical Ophio- 

 pluteiis larva, as has its near relation Ophiactis Balli. 



Ophiactis Savignyi (Miiller and Troschel) 



Ophiactis Savignyi, Koehler, 1914. Meeresfauna Westafrikas. Echinoderma, p. 184, pis. vii, 



fig. 15 ;x, figs. 1-3. 

 O. Savignyi, Mortensen, 1933. Echinoderms of South Africa. Papers from Dr Th. Mortensen's 



Pacific Exped., lxv (Vid. Medd. Dansk Naturh. Foren., 93), p. 348, fig. 58 b. 

 O. Savignyi, Mortensen, 1933. EcJmioderms of St Helena (otfier thati Criiioids). Papers 



from Dr Th. Mortensen's Pacific Exped. 1914-16, lxvi (Vid. Medd. Dansk Naturh. Foren., 



93). P- 442- 



St. I. 16. xi. 25. Clarence Bay, Ascension, 16-27 ^^- '? specimens. 

 St. 283. 14. viii. 27. Annobon, 18-30 m. 4 specimens. 



The species had not hitherto been found at Ascension ; but its occurrence might well 

 be inferred from the facts that it was found at St Helena (Mortensen, 1933) and at 

 Annobon in the Gulf of Guinea ; from the latter locality it was recorded by Koehler, 

 1914. 



Ophiactis nidarosiensis, Mortensen 



Ophiactis nidarosiensis, Mortensen, 1920. Notes on some Scandinavian Echinoderms, with de- 

 scriptions of two new OpJniirids. Vid. Medd. Dansk Naturh. Foren., 72, p. 60. 



O. nidarosie7tsis, Mortensen, 1927. Handbook Echinod. Brit. Isles, p. 200. 



O. nidarosiensis, Mortensen, 1933. Echinoderms of South Africa. Papers from Dr Th. Mor- 

 tensen's Pacific Exped., lxv (Vid. Medd. Dansk Naturh. Foren., 93), p. 346. 



O. nidarosiensis, Mortensen, 1933. Danish 'Ingolf Exped. Ophiuroidea, p. 51. 



St. 399. 18. V. 30. Olf Gough Island, 102-141 m. 2 specimens. 



After the finding of this species in South African seas {op. cit.) there is nothing un- 

 expected in finding it now in material dredged by the ' Discovery II ' oif Gough Island. 

 The specimens agree perfectly with the type from the Trondhjemtjord. 



Ophiactis seminuda, n.sp. 



St. 6. I. ii. 26. Off Tristan da Cunha, 80-140 m. 3 specimens. 



St. 1 1 87. 18. xi. 33. Off Tristan da Cunha, 1 17-106 m. 6 specimens (young). 



Diameter of disk of largest specimen scarcely 3 mm. ; arms about four to five times 

 the diameter of disk. The largest specimen has five arms, the others have six arms and 

 are self-dividing. 



The disk is covered by medium-sized, rather thick scales, among which no primary 

 plates can be made out. One of the specimens has a few pointed spines on the disk, the 

 other specimens have no spines at all on the disk. The ventral interradii are naked in the 

 proximal part. The mouth shields appear to be, typically, almost rhombic, but generally 

 — as is so often the case in self-dividing species — they are more or less irregular in 



