Mr. R. I. Pocock on Neotropical Scorpions. 83 
punctured both finely and coarsely ; manus not carinate, con- 
vex above, its width a little greater than the length of the 
hand-back, sculptured above with large and very fine punc- 
tures which, towards the inner edge, pass into granules ; the 
movable digit longer than the width of the hand; a tooth on 
the immovable as in Ch. amazonicus. 
Legs with minutely granular femora. 
Pectines short, with only six teeth. 
Measurements in millimetres. —Total length 52, of carapace 
8:5, of tail 27 ; width of first segment 4, of second 3°5; length | 
of second 3°4, of fifth 8, width 3; width of vesicle 3-8, height 
3; width of brachium 3, of hand 6+ ; length of hand-back 
5°5, of movable digit 8. 
Two @ examples from Cuenea, in Ecuador (Fraser Coll.). 
Of all the known species of Chactas, [leterochactas Gervaisit 
comes nearest to Ch. Whympert, which has the anterior border 
of the carapace conspicuously notched in the middle. 
Genus CHACTAS. 
The following is a synopsis of the species of this genus 
that are known to me. (‘I’o be used with caution.) 
a. All the segments of the tail, including the first, 
furnished with the normal number of well- 
developed granular keels; the upper surface 
of the trunk and the external surface of the 
legs coarsely granular. 2.0.60 ccs cee cee een: equinoctialis (Karsch). 
b. The lower surface of at least the first caudal 
segment not furnished with granular keels. 
a’. The upper surface of the palpi and carapace 
coarsely granular; vesicle large, impressed 
below ; brachium without an upper internal 
basal tooth ; the proximal tooth on the im- 
movable digit enlarged ............002- Whymper?, sp. 0. 
b'. The lees nearly or quite smooth externally, 
the vesicle less globular and not impressed 
below. 
a”, The third and fourth caudal segments 
clearly carinate below, the second weakly 
carinate; the carapace more coarsely 
granular at the sides; the brachium with 
an enlarged tooth ; the immovable digit 
not basally dentate. 
a’, The upper surface of the abdomen finely 
and closely granular; the caudal keels 
BOM DG ieee sie stoeisjeievole's « 01s nite levipes (Karsch). 
6°, The upper surface of the abdomen 
smooth and polished ; the caudal keels 
BY OAOT ier sere vice: 3.c)«) «0,0. foe nenamen Simonit, sp. D. 
b*, The second and third caudal segments 
