44 Mr. R. I. Pocock on 



Cheloctonus, gen. nov. 

 (PL III.B. fig. 1.) 



Cephalothorax with its median eyes near the middle, the 

 lateral eyes, three in number, on the very edge, as in Hor- 

 murus. 



Sternum pentagonal, a little wider than long, narrower at 

 its posterior angles. 



Stigmata elongate. 



Tail as in Opisthacanthns^ rather stouter than in Hor- 

 mxirus. 



Palp. — Humerus as in ITeterometriis maurus, very convex 

 above, the anterior border reduced to a minimum ; manus 

 intermediate in form between that of, e. g., Opisthacanthus 

 and of, e. g., Scorpio, but rather resembling that of luriis or 

 Urodacus in having the " hand-back " double^ i. e. divided 

 longitudinally by the keel which is found on the hand-back 

 in scorpions of this group ; the lower half of this area is not, 

 however, limited below by a keel, and the keel that defines 

 the upper half is weaker than in Opisthacanthus. 



ChelicercB as in Opisthacanthus^ Hormurus, and Pnlam- 

 naus, i, e. wath the terminal fangs of the movable dactylus 

 subequal in length, the inferior being the longer. 



Tail, tarsi, stigmata, and pectines as in Opisthacanthus. 



This genus is very interesting on account of its annectent 

 qualities. On the wdiole, however, it certainly belongs to 

 the Opisthacanthus group, although in the form of its palpi 

 it approaches Heterornetrus. 



Cheloctonus Jonesii, sp. n. 



Colour olivaceo-piceus above, palpi darker ; legs, cheli- 

 cerce, and caudal vesicle ferruginous ; pectines and genital 

 operculum testaceous. 



Cephalothorax a little wider than long, a little longer than 

 the first two caudal segments, convex from side to side, the 

 sides being considerably sloped, the frontal lobes rounded, 

 the middle of the anterior border with an evenly rounded 

 excision, weakly granular, the median sulcus dividing the 

 ocular tubercle and stopping almost immediately behind it ; 

 the tubercle low, situated just in front of the middle of the 

 upper surface, the eyes separated by a space about equalling a 

 diameter ; the lateral eyes small, subequal, the two anterior 

 contiguous, the posterior separated by a space equal to its 

 own diameter. 



Tergites finely and closely granular, sulcate as in Opistha- 

 canthus. 



