270 



DISCOVERY REPORTS 



With these characteristics it seems necessary to regard these specimens at least as a 

 distinct variety of A. grandi squama. That the specimens from lie de Rolas will prove to 

 belong to this same variety may well be suggested. 



None of the specimens exceed a size of 5 mm. in diameter of disk, with an arm length 

 of ca. 25 mm. 



Amphiura microplax, n.sp. 



St. 27. 15. iii. 26. West Cumberland Bay, South Georgia, no m. 3 specimens. 



St. 144. 5. i. 27. Off mouth of Stromness Harbour, South Georgia, 155-178 m. 5 specimens. 



St. WS33. 2i.xii. 26. 54° 59' S, 35° 24' W, South Georgia, 130 m. i specimen. 



St. MS 68. 2. iii. 26. East Cumberland Bay, South Georgia, 247 m. 6 specimens. 



Diameter of disk apparently not surpassing ca. 5 mm. Arms short, four to five times 

 the diameter of disk. Outline of disk pentagonal, the edge of the interradii straight or 

 only slightly notched. 



Dorsal side of disk covered with moderate-sized scales, among which the six primary 

 plates are usually distinct. The radial shields are short, narrow, separated only by a 



c 



Fig. II. Amphiura microplax, n.sp. Part of oral side (a) and dorsal side (/)). Part of dorsal side of 

 arm joints 3-5 (c). Fig. b drawn from a smaller specimen than that from which Figs, a and c are 

 drawn. 24. 



narrow wedge of scales. Ventral interradii covered with very small scales, which may 

 leave the proximal part slightly bare or cover it completely. Buccal shields rather 

 narrow, with an acute inner angle and a rounded outer lobe. Adoral shields triangular, 

 narrowly or scarcely joining within. Outer mouth papilla conical, pointed; infradental 

 papillae rather small, oval. First ventral plate of medium size, broadly contiguous with 

 the second; the following ones more or less broadly contiguous. The ventral plates in 

 general square, as broad as long, there being, however, some variation in their shape. 

 Dorsal plates contiguous, with convex distal edge, in larger specimens almost biconvex, 



