litlh-lnoicn Neotropical ffcorpions. 471 



strong; teetli in front and a row ot 12 setal pores below; hand 

 a little wider than brachium, its width about two thirds the 

 length of the underhand; hand with 7 granular crests; the 

 external fino;er-keel strong; fingers long, shMid(;r, in contact, 

 the movable quite as long as the cara[)ace and considerably 

 longer than the underhand. 



Pectinal teeth 8-9. 



Measurements in millimetres. — Total length 44 ; length of 

 carapace 6; tail 14; underhand 4v'3 ; movable finger 6*5; 

 width of hand '6. 



Loc. Atoyac in Vera CJruz, ^lexico. 



One specimen of this interesting new species kindly sent 

 to the British ^luseum by Dr. A. Dugfe^. 



Genus Chactas, Gerv. 

 Chactas Simonsi, s[), n. 



Colour entirely black througliout, excej^t tor the tarsi, 

 vesicle, lower side of cephalothorax, and middle of first three 

 abdominal sterna, which are brown. 



Carajxice almost granular throughout, smooth and punc- 

 tured round the median eyes and on the summit of the tubercle ; 

 frontal lobes rounded ; lateral eyes but little prominent, median 

 eyes rather more than a diameter apart. 



Terga sparsely covered in their posterior half with coarse 

 scattered granules, more thickly granular at the sides. 



Sterna smooth, pitted with a itw coarse punctures and 

 obsoletely punctulate. 



Tail tolerably thick; third segment as wide as long, fifth 

 only a little more than twice as long as wide ; first and second 

 segments quite smooth and polished below, third roughened 

 with weak granulation, fourth granular throughout but 

 without median keels, fifth also coarsely granular and 

 normally keeled below ; inferior and superior lateral keels 

 strong and subdentate, inferior lateral keel distinct on third 

 and fourth, just traceable on second segment ; lateral and 

 superior surtace of tail with a few coarse granules, upperside 

 of fifth segment finely granular ; vesicle granular below, wider 

 than filth caudal segment and wider than high. 



Cheloi: humerusgranular above; brachium roughened above, 

 •with low squamiform granules, coarsely granular posteriorly, 

 furnished below with a series of 5 setal pores ; hand as wide 

 as the length of the underhand, its width about four fifths the 

 length of the movable digit, smooth in the middle above, but 

 sculptured with a punctured network, becoming coarsely gran- 

 ular txternally and internally, inner surface coarsely granular. 



