332 DISCOVERY REPORTS 



meridionalis. Accordingly Ophiomastus rotundus is synonymous with Ophiura meri- 

 dionalis (Lyman), which is thus distributed from off La Plata to South Georgia. The 

 fact that there is only one specimen from off the Falkland Islands (St. WS 212) whereas 

 there is a good number of specimens from various places off South Georgia, seems to 

 indicate that the centre of distribution of the species is 

 in the South Georgian area. 



I do not think this species can be referred to the genus 

 Ophiomastus; the long genital slits and the existence of 

 well developed arm combs are characters which do not 

 conform with Ophiomastus, but with Ophiura, to which 

 latter genus this species properly belongs. The tentacle 

 scales are also markedly different from those of typical 

 Ophiomastus. 



None of the present specimens exceed a size of 6 mm. 

 in diameter of disk, which thus appears to be the maxi- 

 mum size. The species is viviparous and hermaphrodite. The 

 male gonads are found at the adradial side of the bursae 



and sometimes also at the interradial side, distally. The F'g- 45- Ophiura meridionalis 

 , f ^1 1 1 J r 1 -4. (Lyman). Type specimen. Dor- 



number of the gonads, male and female, varies to some V-' . , -^ ■'^ ^ 



° sal side. ■ i2'$. 



extent, but generally there are only one or two of each at 



each bursa. The eggs are of the usual large size, ca. o-3-o-4 mm., and there are only few 

 of them ; I have found only some six to eight embryos or eggs in each bursa. In no 

 specimen were young ones found ready to leave the bursa, only such as had the skeleton 

 in an incipient stage. Some of the specimens are infested by a curious Crustacean 

 parasite, probably a Copepod (? Ophioika). It does not castrate its host. 



It may be pointed out that there is some variation in regard to the tentacle scales of 

 the second pore pair ; generally there is only one tentacle scale here, as at the following 

 pores, but not rarely there are two scales, at both sides of the pore. The specimen 

 figured is unusual in having two scales at one pore, only one at the other. The disk is 

 often conspicuously swollen, almost hemispherical, recalling to some degree that of 

 Ophiopyrgus. The edge of the disk is usually rather sharp, marking the limit between 

 the flat underside and the more or less elevated dorsal side. 



Ophiura Rouchi (Koehler) 

 (Plate VIII, figs. 6, 7) 



Op/iioglypha Rouchi, Koehler, 191 2. IP Exped. Antarct. Franfaise. Echinodermes, p. 107, 



pi. ix, figs. 11-12. 

 Ophiura Rouchi, Koehler, 1922. Austral. Antarct. Exped. Echinod. Ophiuroidea, p. 52, pi. 



Ixxxv, figs. 1-2. 

 O. Rouchi, Hertz, 1926. Deutsche Siidpolar-Exped. Ophiuroiden, p. 23. 



St. 195. 30. ill. 27. Admiralty Bay, King George Island, South Shetlands, 391 m. 4 specimens. 



