342 DISCOVERY REPORTS 



swollen than in the specimens from South Georgia. As, however, there is only one young 

 specimen, 4 mm. in diameter of disk, from that station, I give this identification with 

 some reserve. 



This species is viviparous mid hermaphrodite. There is one sausage-shaped testis at the 

 adradial side of the bursa, sometimes also a second smaller one proximal to the large 

 one. There is one female gonad at the interradial side of the bursa, with only one egg 

 developing at a time, and it is almost certain that the development is intra-ovarial ; the 

 developing eggs are large, 0-5 mm. in diameter. 



Amphiophiura gibbosa, n.sp. 

 St. 175. 2. iii. 27. Bransfield Strait, South Shetlands, 200 m. 3 specimens. 

 Diameter of disk of the largest specimen 6-5 mm., the arms rather stout, ca. 18 mm. 

 in length, thus about three times the diameter of the disk. Disk covered by rather coarse 







c 



Fig. 51. Amphiophiura gibbosa, n.sp. Part of oral side {a) and dorsal side {h). 

 Part of arm in side view (c). x 12. 



scales, among which the polygonal central plate and five primary radial plates are con- 

 spicuous, particularly the latter, which form a wedge between the proximal ends of the 

 radial shields. 



These primary radial plates, together with the radial shields, are conspicuously 

 elevated, and produce a somewhat gibbous appearance, recalling Ophiosteira Senoiiqid. 

 The radial shields are contiguous in their distal half. In the younger specimens there is 

 a single series of plates in the interradii, in the larger specimen several small plates have 

 been added. No large plate on the edge of the interradii, also the ventral interradii are 

 covered by small plates only, besides the buccal shields, which are fairly large, occupying 

 about half of the interradius. In one case the proximal end of the buccal shield has been 

 separated off as a small plate. Adoral and oral plates (jaws) of about equal size, in the 



