Mr. R. I. Pocock on Neotropical Scorpions. 89 



inferior lateral keels present too on all the segments^ and finely- 

 granular at least on the fourth; the inferior median keels 

 entirely obsolete on the first, just appearing on the second, 

 still stronger on the third, plainly visible and granular on the 

 fourth, this segment consequently having eight distinct 

 granular keels ; the fifth segment flat above behind, granular 

 at the sides, with squared granular edges; lateral surface also 

 granular, with indistinct median lateral keel, the lower surface 

 with three inferior granular keels, and the intervening spaces 

 also serially granular ; vesicle moderately large, wider than 

 the fifth segment, and almost as wide as the second ; its 

 height is about equal to the width of the fifth ; thickly 

 granular beneath, sm.ooth above; aculeus more than half the 

 length of the vesicle. 



Palpi elongate ; the humerus granular above, the brachium 

 granular above, smoother behind, with a conspicuous bifid 

 denticle above at the base of the anterior surface ; manus 

 rather narrow, not twice the width of the brachium, indis- 

 tinctly keeled above and marked with very short series of 

 minute granules ; the length of the hand-back much greater 

 than the width of the hand, the digits long, the basal tooth on 

 the immovable digit scarcely larger than the rest. 



Legs nearly smooth, the femora of the last pair only very 

 weakly granular. 



Fectines short, with 6-7 teeth. 



Measurements in millimetres. — Total length 53, length of 

 carapace 8*5, of tail 27. of fifth segment 7*o, width 2*2 ; width 

 of vesicle 2*8 ; width of brachium 2"7, of hand 4'5 ; length of 

 hand-back 7, of movable digit 8. 



Two female specimens from Venezuela. 



Chactas chrysopus^ sp. n. 



Colour piceo-ferruginous ; legs flavous. 



Carapace as long as the anterior three caudal segments, 

 very smooth, very minutely granular at the sides; the front 

 border with a shallow emargination ; the median eyes large, 

 the distance between ihem about equal to a diameter ; the 

 anterior lateral eye large and very prominent ; the posterior 

 smaller and separated from it by a distance about equal to its 

 own diameter. 



Tergites entirely smooth, the last only very minutely 

 granular at the sides, with two tubercles on each side. 



Sterna entirely smooth and polished. 



2^ail about three and a half times the length of the cara- 

 pace, the third segment as long as wide, the first a)id second 



