334 DISCOVERY REPORTS 



but prefer to designate it as a variety (it cannot be referred to any of the other known 

 species of Ophiiira from Antarctic seas). 



Concerning the sexual character of the variety, as wtW as the typical flexibilis, I can 

 only state that the eggs are of the usual large size, ca. o-2-o-3 mm., and rich in yolk; 

 but whether the species, or the variety, is viviparous or not cannot be decided from the 

 scanty material at hand. 



Ophiura serrata, n.sp. 



St. 175. 2. iii. 27. Bransfield Strait, South Shetlands, 200 m. 4 specimens. 



St. 19s. 30. iii. 27. Admiralty Bay, King George Island, South Shetlands, 391 m. i specimen. 



Diameter of disk 5-5 mm. Arms all broken, but apparently not more than about three 

 times the disk diameter. They are triangular in section, the underside quite flat, the 

 dorsal side keeled, but the keel is not sharp. 



Dorsal side of disk rather flat, covered by large flat, imbricating scales, among which 

 the primary plates are very conspicuous, forming in the younger specimens a very 

 regular rosette. With age the primary plates evidently become separated by some smaller 

 plates. Radial shields contiguous distally or nearly so. Ventral interradii with few, 

 irregular plates, one in the middle, outside the buccal shield, somewhat larger than the 

 others. Buccal shield rounded, with a small peak within. Adoral and oral plates of the 

 usual shape. Mouth papillae three to four on each side of jaw, of the usual square shape. 

 First ventral plate large, pentagonal, with convex outer edge. Second ventral plate 

 scarcely in contact with the first, the following plates widely separated. Dorsal arm- 

 plates rounded hexagonal in the proximal part of arm, gradually becoming longer and 

 separated, pointed proximally and with the outer edge convex. The lateral plates, which 

 are hardly at all swollen, carry three rudimentary, equal-sized and equidistant spines, 

 at most the upper one slightly removed from the others. Only the two first pores well 

 developed ; from the third there are two small tentacle scales, from about the fifth only 

 one. Genital slits well developed, reaching to the edge of the disk, with fairly well 

 developed papillae along the genital scales; arm combs very little developed, at most 

 two to three small papillae being visible from above. Colour of dried specimens whitish. 



A conspicuous feature is found in the dorsal arm plates. They are separated by a 

 rather deep furrow, which causes the dorsal outline of the arm as seen in profile to be a 

 low serration, the plate itself being quite flat in outline (Fig. 47 c). 



As regards the sexual characters of this species I can give no information beyond the 

 fact that in one of the specimens, an interradius of which was opened, I found the gonads 

 to contain only very few young, yolky eggs ; it appeared that they would probably grow 

 to the usual rather large size. Whether the species is viviparous cannot be ascertained 

 from such poor evidence. 



The specimen from St. 195 is somewhat larger, 7 mm. diameter of disk, and has some 

 more small plates on the disk, the primary plates being wholly separated. The dorsal 

 arm-plates are somewhat different in outline from those of the typical form (Fig. 47 d), 

 and the lateral plates are rather distinctly swollen. Otherwise it agrees with the typical 



