88 Mr. E. T. Pocock on Neotropical Scorpions. 



more than half the length of the liand-back, which itself 

 equals the length of the movable digit ; the manus convex 

 above, not keeled, granular internally and minutelj reticulato- 

 granulate above ; the digits not dentate. 



Legs almost entirely smooth ; the lower edge of the femora 

 granular. 



Pectines short, with 7 teeth. 



Measurements in millimetres. — Total length 53, of carapace 

 7*5, of tail 27 ; width of first segment 3*4, of fifth 2'5 ; 

 width of brachium 2'5, of hand 4 ; length of hand-back and 

 of movable digit 7. 



Loc. Colombia. Two female examples, one collected by 

 M. Goudot, the other from the collection of the late Count 

 Keyserling, in honour of whom I name the species. 



This species is nearly related both to Gh. Van Benedeniij 

 Gervais, and to Ch. lepturus of Thorell. From the former it 

 may be recognized at once by having the superior caudal 

 keels evident and denticulate, and by having the humerus, 

 brachium, and manus and last tergite granular; moreover, in 

 the female of Van Benedenii the tail is longer and the palpi 

 are more robust, the width of the hand as compared with the 

 length of the hand-back being as 5 : 7'3. 



From the Museum example that I identify as lepturus, 

 Thorell, Keyserlingii may be recognized by having the hand 

 unkeeled, the palpi and last tergite more granular, the upper 

 surface of the tail more deeply excavated and more granular, 

 and the superior and supero-lateral keels better developed 

 and more granular, 



Chactas Simonii, sp. n. 



Colour piceo-ferruginous, legs paler. 



Carapace smooth on the summit of the prominences, granu- 

 lar over the rest of its surface, nearly as long as the anterior 

 three caudal segments j the median eyes of average size, sepa- 

 rated by a space that is rather greater than a diameter j the 

 distance between the lateral eyes about equal to a diameter ; 

 the anterior lateral eye prominent. 



Tergites smooth, the last finely granular, with two 

 tubercles on each side. 



Sternites smooth and polished. 



Tail less than three and a half times the length of the 

 carapace, narrowed posteriorly, the second segment as long as 

 wide, the upper surface of the segments nearly flat and 

 smooth, the superior and supero-lateral keels developed and 

 granular, the former with enlarged terminal granule; the 



