340 DISCOVERY REPORTS 



Dictenophiura Skoogi (Koehler) 



Ophiura Skoogi, Koehler, 1923. Sur quelques Ophiures des cotes de V Angola et du Cap. Goteborg. 



K. Vet. Vitterhets-Samhalles Handlingar, xxv, 5, p. 11, figs. lo-ii. 

 Dictenophiura Skoogi, Mortensen, 1933. Echinoderms of South Africa. Papers from Dr Th. 



Mortensen's Pacific Exped., lxv (Vid. Medd. Dansk Naturh. Foren., 93), p. 390, fig. 87 b. 



St. 279. 10. viii. 27. Off Cape Lopez, French Congo, 58-67 m. 15 specimens. 



There can be no doubt that these specimens are identical with Koehler's Ophiura 

 Skoogi. Another question is whether this O. Skoogi differs really so much from the North 

 Atlantic O. carnea that it can reasonably be regarded as a separate species. Koehler 

 {op. cit., p. 14) points out quite a number of characters in which O. Skoogi differs from 

 O. carnea. But I do not think a single one of them holds good, except, perhaps, that the 

 radial shields are in general slightly larger in O. Skoogi than in carnea. The only notice- 

 able difference I find is that the lateral plates are more swollen in Skoogi than in carnea, 

 and also that the dorsal arm-plates are somewhat more swollen in the former. In my 

 Echinoderms of South Africa I have given a figure showing that the buccal shields are 

 considerably elongated in O. Skoogi, but this is no constant feature; there is so much 

 variation in the size of the buccal shields that in this respect no reliable difference be- 

 tween Skoogi and carnea (and anoidea) can be found. In the work cited above I have 

 further stated that O. Skoogi differs from both carnea and anoidea in the primary disk 

 plates being "wholly surrounded by small plates", which they are not in the two other 

 species. This is a mistake, partly in Koehler's description, which states that these plates 

 are " separees les unes des autres par une rangee de petites plaques ", partly in Koehler's 

 fig. II, which apparently shows the large plates each surrounded by a circle of smaller 

 plates. They are not so; but all the plates, in the specimens preserved in alcohol, are 

 darker in the centre, a broad edge appearing whitish. This produces the effect seen in 

 Koehler's fig. 11. The same feature is also observable in both carnea and anoidea. 



There thus remain, as the only characters distinguishing O. Skoogi from carnea, 

 the more swollen dorsal and lateral arm-plates, and in addition the slightly larger radial 

 shields, characters rather insufficient for specific distinction. I think that this form from 

 the tropical coast of West Africa represents merely a variety of the North Atlantic carnea, 

 which latter is recorded from as far south as the Cape Verde Islands. Before, however, 

 the specific value of O. Skoogi is finally decided I think it desirable to have specimens 

 from the north-west coast of Africa for comparison, and for this reason I shall for the 

 present keep it as a separate species. 



It may be added that this species (or variety) has separate sexes and is not viviparous, 

 as holds good also of O. carnea and anoidea. 



Amphiophiura Rowetti, G. A. Smith 



Amphiophiura Rozvetti, G. A. Smith, 1923. Report on the Echitioderms coll. during the voyage of 

 H.M.S. 'Quest'. Ann. Mag. Nat. Hist., 9 Sen, xii, p. 370. 

 St. 20. 4. iii. 26. 14-6 miles N 41" E of Cape Saunders, South Georgia, 200 m. i specimen. 

 St. 27. 15. iii. 26. West Cumberland Bay, South Georgia, iiom. 3 specimens. 

 St. 42. I. iv. 26. Off mouth of Cumberland Bay, South Georgia, 120-204 m. 3 specimens. 



