414 Mr. R. T. Pocock on some 



fifth caudal segment, punctured, weakly granular in the 

 hollows of the upper surface and at the sides; terga also 

 punctured. 



Tail about four times as long as the carapace ; second 

 segment a little longer than wide, fifth a little more than 

 twice as long as wide; superior and superolateral keels 

 strong and granular, the three inferior keels strong and 

 granular on the third, fourth, and fifth, weakly granular on 

 the first and second segments ; the median keel obsolete on the 

 anterior half of the first segment; vesicle wider than the fifth 

 segment, smooth, punctured ; aculeus long and normally 

 spiniform in its distal half. 



Chelce punctured ; humerus with normal granular keels 

 above and in front ; the upper and lower anterior crests on 

 brachium granular ; hand flat above, with weak median 

 keel, strong but smooth external finger-keel; external keel 

 of hand-back strong and granular ; movable finger longer 

 than carapace. 



Genital operculum cordate, sulcate in front. 



Pectinal teeth 10. 



<$ . — Not very different from female, but rougher, with 

 close punctuation on the tergites and carapace; tail longer, 

 the carapace a little shorter than its first and second segments; 

 hand a little wider, its width about equal to the length of the 

 hand-back ; inner edge of the hand granular. 



Genital operculum transversely oval, divided. 



Pectinal teetli 13. 



Measurements in millimetres. — $. Total length 35; cara- 

 pace, 4'8, tail 18, movable digit 5. 



$ . Total length 82 ; carapace 4*5, tail 19. 



Loc. Aden {E. W. Gates and Col, Yerbury). 



1 formerly regaided the specimens here described as im ma- 

 lure examples of II. Upturns known from Bagdad. No 

 doubt, however, they are adult. The species may be recog- 

 nized at once from Upturns by having the aculeus normally 

 spiniform, and not short and subcorneal as described by 

 Kraepelin (JB. Hamb. xi. p. Ill, 1894). The male of 

 Upturns, moreover, has the vesicle peculiarly modified and 

 elongate. 



Genus Ueodacus, Pet. 



Urodacus macrurus, sp. n. 



J . — Colour. Carapace deep ferruginous, tergites darker ; 

 legs, chela?, and tail paler yellowish red; fingers dark. 



Carapace as long as the first and one quarter of the second 



