1890.] OF THE FAMILY BUTHID^. 139 



laterally in the posterior half t'rom the central sulcus ; ocular tu- 

 bercle with the ridges formed by the sulcus granular. 



Tergites granular throughout, the granules in the posterior half 

 of each much larger than in the anterior ; each, except the last, 

 marked in the middle line behind by a granular keel, the last 

 bearing in its anterior half a median prominence and on eacli side 

 two keels which anteriorly disappear in the general granulation of 

 the tergite. 



Sternites. The anterior three smooth ; the fourth slightly gran- 

 ular only at the sides ; the fifth somewhat coarsely granular and 

 bicarinate in its posterior half. 



Tail robust, nearly five times as long as the cephalothorax ; upper 

 surface not deeply excavated and very finely granular ; lateral and 

 inferior surfaces coarsely granular throughout and sparsely hairy ; 

 the first segment marked with ten strongly and evenly granular 

 keels, the second, third, and fourth with eight similar keels, the fifth 

 with five keels, whereof the two superior are weak. Vesicle smooth 

 above, somewhat coarsely and subserially granular beneath, the 

 spine long and slender; the aculeus stout and curved. 



Palpi hairy ; upper surface of humerus minutely granular 

 throughout and bounded in front and behind by a series of coarse 

 granules ; anterior and posterior surfaces armed with small granules 

 and larger tubercles ; inferior surface finely granular proximally : 

 brachium granular and cariuate behind and above, sparsely tuber- 

 cular in front, minutely granular beneath : manus smooth and 

 rounded, neither granular nor costate, about equalling the brachium 

 in width : dactyli curved, nearly twice as long as the " hand-back," in 

 contact throughout, neither sinuate nor lobate ; the arrangement of 

 teeth approximately the same as in the preceding species. 



Chelicerce with dentition as in the preceding species. 



Zye^s with ye;«o?a feebly granular in front, cariuate and granular 

 above and below ; patellce cariuate and granular anteriorly ; tihice of 

 the first three pairs unarmed, of the fourth pair spurred. 



Pectines not extending so far as the distal extremity of the fourth 

 coxae, armed with 20 or 21 similar teeth. 



Stigmata slit-like. 



Measurements in inillimetres of (2) specimen. — Total length 76 ; 

 cephalothorax, length 8'5, width 9"5 ; distance of eyes from poste- 

 rior margin 5 : tail, length 43 ; of 1st segment 5 ; of second 6 ; of 3rd 

 ()'3 ; of 4th 7".5 ; of 5th 8'5 ; of vesicle 4-.5. Palpi — humerus, length 

 7; brachium, length 8, width 3"3 ; manus, width 3 ; "hand-back," 

 length 5 ; movable dactyl us, length 9. 



A single specimen in the Museum collection taken by Mr. F. J. 

 Jackson at Taveita, Kilima-njaro. 



This species is closely allied to, and may possibly jirove to i)e 

 only the female of, R. dentatus. But the under surface of the 

 fourth and fifth caudal segments is furnished with distinct granular 

 keels ; mR. dentatus these segments are said to have only the upper 

 side keeled. 



