211 



16 (17) The fifth joint of the tail broadly excavated above, its upper 



margins forming an elevated keel Rhopalurus. 



17 (16) The upper margins of the fifth joint of the tail rounded, not 



forming an elevated keel Centrums, 



18 (1) Sternum either very short, forming a transverse falciform band or 



line, or else with parallel sides and subpentagonal. 



19 (24) Sternum very short, forming a transverse falciform band or line 

 curved backwards between the coxae of the second pair of legs and the 

 genital plates. [Intermediate plates of the combs generally (al- 

 ways?) numerous, most of them rounded and small (little or no 

 larger than the fulcra), and arranged in 1-3 longitudinal rows. Both 

 fingers of the mandibles provided with a single row of teeth. Lateral 

 eyes three or two (?) on each side, small. No tooth or spine under 

 the sting.] Fam. II. Telegonoidae. 



20 (23) Tail without keels on the underside. 



21 (22) The fifth joint of the tail provided on the underside, near the 

 apex, with a large, depressed, almost semi-elliptical area, rounded in 

 front, and limited by a row of small teeth or granules . Bothriurus. 



22 (21) The fifth joint of the tail smooth below, without a depressed 



semi-elliptical area Telegonus. 



23 (20) Tail keeled at least on the under side of the fifth joint. 



Cercoplionius. 



24 (19) Sternum with parallel sides, subpentagonal. [The movable man- 

 dibular finger provided with one or two rows, the immovable with a 

 single row of teeth.] 



25 (28) Sternum rather small, about double as broad as long. Inter- 

 mediate plates of the combs generally (always?) numerous, most of 

 them rounded and small (little or no larger than the fulcra), and ar- 

 ranged in 1-3 longitudinal rows. The hands subfusiform or ovate, their 

 height or thickness in general greater than their least breadth. [Three 

 (or four) lateral eyes on each side, forming a row curved inwards. 1 No 

 spine or tooth under the sting.] .... Fam. III. Vejovoidao. 



26 (27) The movable mandibular finger provided with a single row of 

 teeth in the upper margin. Dorsal eyes placed rather far in front 2 of 

 the centre of cephalothorax Vejovis. 



27 (26) The, movable mandibular finger not only provided with a row of 

 teeth in the upper margin, but also with a tooth in the under margin. 

 Dorsal eyes not far removed from the centre of cephalothorax. 



Hadrurus, 



1 Vccording to Peters, these scorpions have two principal lateral eye- and one or two 

 accessory eyes. 



- The measures are taken from the eyes to a straight line tangent to the anterior 

 margins of the frontal Lobes, ami to the middle of the posterior margin of the cephalo- 

 thorax. 



