348 



horizontal, the apex sharply truncate and more or less concave. 

 Pedicel 1-jointed, surmounted by a scale or node ; abdomen more 

 or less oval, the basal segment not forming half its length. 



$ . Head and pedicel as in the . Ocelli present. Thorax 

 more massive ; prothorax short, its posterior margin arched ; 

 posterior lateral angles reaching back to the base of the wings ; 

 mesonotum and scutellum long, raised and gibbous ; metanotum 

 depressed below the level of the scutellum. Abdomen longer and 

 more massive. Fore wing with one marginal and one cubital cell. 



d 1 . Mandibles narrower than in the ; antennae 13-jointed ; 

 ocelli and eyes large and prominent. Thorax as in the $ , but 

 more massive in proportion. Node of pedicel thicker ; abdomen 

 proportionately slightly more elongate ; external genitalia very 



This widely spread genus has the dimorphous, often poly- 

 morphous. In some species the major has a remarkably broad 

 massive head and strong mandibles. 



Key to the Species. 



A. Thorax viewed from side forming a 



regular arch. 

 . Pubescence on sides of head and 



beneath long, forming a beard 



b. Pubescence on sides of bead and beneath 



short, not forming a beard. 

 a'. Head, tborax and abdomen black. 

 ' J . Tibiae of the legs prismatic. 



a 3 . Tibiae without spines beneath . . 

 b 3 . Tibiae of the legs with spines 



beneath. 

 '. Abdomen covered with long 



recumbent yellowish hair 

 I 4 . Abdomen covered with sparse 



erect hairs. 



3 . maj. Length 11-16 mm. 

 min. with head poste- 

 riorly narrow but not con- 

 stricted to form a collar . . 

 i 5 . maj. Length 17-21 mm. 

 min. with the head poste- 

 riorly constricted so as to 



form a collar 



b-. Tibiae of the legs compressed but 



not prismatic. 



3 . Abdomen with a fine thin seri- 

 ceous pubescence. 

 fl 4 . Length ty maj. under 7 mm. ; 



pubescence grey 



6*. Length maj. over 9 mm.; 

 pubescence yellowish 



Fig. 108. Outline thorax: 

 C. compressus. 



C. barbatus, p. 362. 



C. lamarcki, p. 365. 

 C. japonicus, p. 370. 



C. compressus, p. 351. 

 C. angusticollis, p. 366. 



C. linghami, p. 367. 

 C. parta, p. 364. 



