6 Annals of the South African Museum. 



Carapace distinctly emarginate in the middle of the truncated 

 anterior edge ; the granulation of the sides very much coarser. 



Terga smooth, finely granular at the sides ; last segment coarsely 

 granular, except along the elevated median line. 



Sterna perfectly smooth and polished. 



Cauda. In the first two segments the ventral surface and the 

 infero-lateral and median keels are perfectly smooth, and the 

 median keels are not separated by a groove ; cauda longer than the 

 (much contracted) abdomen ; vesicle not longer than the fifth 

 caudal segment. 



Palps. Humerus very coarsely granular on the posterior part of 

 upper surface, nearly smooth on the anterior part ; anterior and 

 inferior surfaces with a few small and some large granules ; the 

 superior keel of brachium smooth along the top but undulate at 

 the sides, much stronger than the uppermost keel of the posterior 

 side, the sloping surface between these keels forming a part of the 

 rounded posterior surface rather than a distinct upper surface ; 

 hands denticulate on the inner edge. 



Tarsi of third and fourth pair of legs with 3 external and 6 

 internal spines below. 



Operculum subcordate, scarcely broader than long, emarginate 

 posteriorly but not cleft longitudinally. 



Pectines not extending beyond apex of last pair of 00x93, furnished 

 with 24 teeth. 



Measurements in Millimetres. Total length 135 ; greatest length 

 of carapace 22 ; width of carapace 20^ ; distance of eyes from 

 anterior median edge 15^- ; width of hand 14 ; length of hand-back 

 13|, of movable finger 21, of tail 77 ; width of first caudal segment 

 7i, of fifth caudal segment 4f , of vesicle 6^. 



Male (dry}. 



Two specimens, which are undoubtedly adult males of this species, 

 differ from the female in the following characters : 



Colour of fingers reddish brown or blackish ; finger-keel not 

 blackened ; cauda yellowish or yellowish brown. 



Carapace about as long as the first and second caudal segment 

 and one-third or one-fourth of the third. 



Terga finely granular on seg. 1-6. 



Sterna apparently smooth (to the naked eye) but provided with a 

 number of exceedingly minute scattered granules, such as are occa- 

 sionally found in the male of 0. pallidipes. 



Cauda with a few minute scattered granules on ventral surface of 



