1907.] CRUSTACEA OF THE THIRD TANGANYIKA EXPEDITION. 



269 



Front less than one-third the width of the carapace, its margiii 

 perlated, and with a stout sj)ine at each extremity. Sub-orbital 

 spines short and stout ; a small spine on the descending process 

 of the front. Orbits small, -16 width of carapace ; orbital margins 

 perlated. Eyes and peduncles small. Chelipeds in both sexes 

 unequal ; merus trigonous, with distally a prominent spine on 

 the antei'ior margin, and a small spine or tubercle on the ventral 

 margin ; carpus with two spines on inner margin and one above 

 the point of articulation with the hand. Hands and fingers 

 somewhat compressed, the dorsal border being keeled and granu- 

 lated ; the ventral border in the larger chela characteristically 

 arcuated at the junction of the poUex. Fingers pointed and 

 slightly hooked ; those of the larger chela gape, and have a pair 

 of large fiat crushing-teeth proximally, with a series of rather 

 smaller ones distally. In the smaller chela the teeth are fairly 

 uniform and of moderate size. Ambulatory legs of moderate 

 length. Colour, in life, yellowish brown, with irregular blotches 

 of darker brown on the carapace. 



Text-fie-. 84. 



Flafi/thelphusa armata, large male. X f. 



Milne-Edwards and Miss Rathbun give the detailed dimensions 

 of an adult female (type specimen), but as we now possess for 

 the first time pai-ticulars of males, the measurements of an 

 adult male — the largest known specimen^ — are included here. 

 In this individual (text-fig. 84) the size of the larger chela is very 

 striking, the length of the hand and pollex being greater than the 

 whole breadth of the carapace. 



Proc. Zool. Soc— 1907, Ko. XIX. 19 



