282 



CIOIJTDELTI)^. 



Genus DEROCRANIA. 



Derocrania, Chaudoir, Bull. Soc. Moscou, 18C0, pp. 284 & 29? 

 W. Horn, Spol. Zeyl. 1904, p. 39. 



Type, Derocrania clohrni, Chaud. ( = scitiscabra, Walk.). 



The insects belonging to this genus are smaller and more slender 

 than those belonging to the genus Tricondyla, some of them being- 

 very delicate. The resemblance to ants of various species is very 

 striking; in many characters they closely resemble Tricondyla, but 

 may be known by having the head between the eyes less exca- 

 vate, and in several cases level, smooth, and even slightly convex, 

 and the vertex more or less strongly strangulate behind, without 

 the parallel neck which is characteristic of Tricondyla. The 

 pronotum is much more slender and elongate, and often, but not 

 always, produced into a distinct and more or less elongate colium 

 in front, as in Neocollyris' the sculpture of the pronotum is in 

 some cases distinctly rugose transversely ; elytra elongate, more 

 or less distinctly widened behind, sometimes very strongly raised 

 behind, sometimes almost flat, with very variable sculpture ; 

 antennae and legs very long aud slender ; apex of the last abdo- 

 minal sternite pointed in the female ; the apophysis or armature 

 of the posterior margin of the last tergite appears to be variable 

 and much more marked in some species than in others. 



The whole of the species which have been hitherto described 

 are confined, to the Indian region, and ten of them have occurred 

 only in Ceylon ; they ma)" be separated as follows : — 



I. Elytra with strong longitudinal sulci, 



very gibbose ; pronotum with a dis- 

 tinct colium. 



i. Pronotum shorter and broader ; sulci 



and elytra shallower and less 



regular honorei, Fleut., p. 283. 



ii. Pronotum longer and narrower: 



sulci of elytra deeper and more 



regular longesulcata, W. Horn, 



II. Elytra with longitudinal sculpture, [p. 284. 



but with the impressions separate, 

 and more or less irregularly confluent 

 in parts, cateniform : pronotum coni- 

 cal, without distinct colium brevicollis, W . Horn, p. 285.. 



III. Elytra punctured or transversely 

 rugose. 



i. Forehead not excavate ; pronotum 

 with a distinct colium. 

 1. Punctuation of elytra very fine 

 and evanescent behind ; slender 



and very delicate species 



A. Colium of the pronotum shorter; 

 elytra smooth from just behind 



middle nietneri, Mots., p. 285. 



