318 On Ethiopian Species of Ischnurinse. 



the length of the carapace ; none of the segments distinctly 

 keeled, marked below with series of pores ; the inferior surface 

 of the fifth segment scarcely granular ; the upper surface of 

 the tail mesially excavated, the sides a little uneven, hardly 

 granular ; vesicle smooth below. 



Chelce nearly smooth above ; humerus only minutely 

 granular above, its anterior surface and the upper and lower 

 crests which define it distinctly granular ; smooth below ; 

 brachium smooth above, but reticulated, its anterior crests 

 granular, the basal anterior tooth prominent ; hand flat, long 

 and narrow, nearly parallel-sided, its width only a little more 

 than half the length of the hand-back ; upper surface reticu- 

 lated, inner surface distinctly granular or denticulate, outer 

 surface more than three times as long as high, granular and 

 traversed by a long crest ; lower surface smooth, reticulated ; 

 digits short, movable about two thirds the length of the hand- 

 back, with a sharp basal tooth. 



Legs with femora finely granular externally ; tarsi with a 

 median row of spicules and lateral rows of four setse. 



Pectinal teeth 9. 



Measurements in millimetres. — Total length 38 ; length of 

 carapace 6, of tail 13*5, of hand-back 6'5 ; width of hand 3*5; 

 length of movable digit 4 - 2. 



Loc. Mombasa {D. J. Wilson). 



This species is of peculiar interest, inasmuch as the only 

 other species of the genus, Iomachus Iceviceps (Poc.) *, is an 

 inhabitant of Southern India. The two species may be 

 readily recognized by the following features : — 



a. Cuticle densely and finely punctured; tail longer, its 



first three segments exceeding the length of the cara- 

 pace even in the female ; vesicle yellow and higher ; 

 hand wider, its inner surface less strongly granular, 

 outer surface without a median granular crest, two 

 pores above at base of immovable finger; movable 

 digit longer, almost as long as the hand-back ; with 



basal lobe ; pectines with 3-6 teeth Iceviceps, Poc. 



S. India . 



b. Cuticle not densely punctured ; tail shorter, its first 



three segments in the male less than the length of the 

 carapace; vesicle fuscous, thinner; manus longer, 

 more coarsely granular internally, with a median 

 granular crest on the outer surface; movable digit 

 only about two thirds the length of the hand-back 

 and armed with sharp basal denticle ; three pores at 

 the base of the immovable digit above ; pectinal 



teeth 9 politus, sp. n. 



Mombasa. 



* Ann. & Mag. Nat. Hist. 1S90, vol. v. p. 242, pi. xii. fig. 1 {Hor- 

 murus). 



