298 DISCOVERY REPORTS 



specimen from St. 182 the dorsal side of the arms also shows a faint trace of orange 

 colour. 



The species has separate sexes, and is not viviparous. 



The type specimen was taken at Port Lockroy, Palmer Archipelago, 70 m. ; the species 

 is thus as yet known only from the Palmer Archipelago and South Shetlands, 70- 

 ca. 300 m. 



From St. 182 there are a number of very young Ophiurids, which are not identifiable 

 with certainty; but there are indications that they would have developed into Am- 

 phiurids, and not improbably Amphiura peregrinator . Unfortunately, the intermediate 

 stages are lacking, so that certainty cannot be reached, and it seems, therefore, not 

 desirable to give a description of these young specimens, the general appearance of 

 which is not at all Amphiurid-like. 



Family OPHIOCHITONIDAE 

 Ophionereis sexradia, n.sp. 

 St. 283. 14. viii. 27. Off Annobon, Gulf of Guinea, 18-30 m. 9 specimens. 



Diameter of disk of largest specimen 6 mm. ; arms six, about four times the diameter 

 of the disk. 



Scales of dorsal side of disk very small, but distinct, imbricating; they are slightly 

 larger round the radial shields, which latter are small, about one-quarter the length of 

 the disk radius, oval, separated by several rows of scales. No primary plates discernible. 

 The ventral interradii look as if they were naked in the proximal half; in reality they are 

 scale-covered throughout, as can be substantiated in dried specimens, but the skin is 

 more or less conspicuously dark coloured in this proximal part, which conveys the im- 

 pression that it is naked. Buccal shields spade-shaped, with a short, rounded distal 

 lobe. Adoral plates narrow, but joining within. Usually four equal-sized mouth papillae 

 on each side of jaw. Ventral arm plates somewhat longer than broad, contiguous, with 

 convex distal edge and sides with a re-entrant curve. Dorsal arm plates broadly con- 

 tiguous, somewhat longer than broad, with nearly straight distal edge. The supple- 

 mentary plates of moderate size, but quite distinct. Three slender, equally long arm 

 spines, slightly curved and flattened, of about the length of an arm joint. One large, 

 oval tentacle scale. Colour in alcohol: the disk light greenish, with an elongate 

 brownish spot at the base of each arm. Underside whitish, apart from the above 

 mentioned dark proximal part of the interradii, this colour being evidently due to the 

 stomach shining through the delicate body wall. Arms (and spines) whitish, or cream- 

 coloured, with an irregular band of brownish on every fifth to sixth joint, the inter- 

 vening part dotted with small brownish spots, in the main arranged in two longitudinal 

 series. 



Although in regard to the configuration of the plates and its general characters this 

 species does not diflPer markedly from the other known species of the genus Ophionereis, 

 it does so by having six arms, all the other species having five arms. Moreover, it appears 



