342 RHYNCHOPHORA. [Ceuthorrhynchus. 



species are so closely allied that several authors have had consider- 

 able doubt as to their being specifically distinct ; the following table 

 will be found of considerable service, but as some of the chief characters 

 are not very obvious, it will be found more useful for particular groups 

 than for the species taken as a whole. 



I. Femora not toothed. 



i. Tavsal claws dentate beneath or appendiculate on 

 their inner side. 



1. Rostrum black. 



A. Elytra with small tubercles before apex . . C. SYKITES, Germ. 



B. Elytra without tubercles before apex. 



a. Elytra black, rather shining, with simple 



rows of white setae C. SETOSUS, Boh. 



(atomus, Boh.) 



b. Elytra covered with moderately close grey 



scales C. CONSTRICTUS, Marsh. 



2. Rostrum bright red ; form very short and con- 



vex with coarse elytral striae C. EBIC.E, Gyll. 



ii. Tarsal claws simple, rather slender. 



1. Elytra with a band of white scales extending the 



whole length of the suture (0. suturalis, F.) 



2. Elytra without sutural band of white scales. 



A. Elytra with a white patch of scales at 



scuti Hum C. COCHLEABI.2B, G-yll. 



B. Elytra without a white patch at scutellum. 



a. Upper surface thickly clothed with grey 



scales C. ASSIMILIS, PayJc. 



b. Upper surface without or almost without 



scales, shining and apparently glabrous, 

 a*. Elytra bright blue or violet; punctures 



of stria? finer, of thorax coarser ; thorax 



with a slight central furrow C. EKYSIMI, F. 



b*. Elytra with a very slight bluish green 



or aeneous reflection ; punctures of strie 



coarser, of thorax finer ; thorax without 



central furrow C. CONTRACTUS, Marsh. 



II. Femora, at all events the posterior pair, toothed, as 



a rule plainly, but in one or two cases with the 

 teeth obsolete in one sex.* 

 i. Tarsal claws dentate beneath or appendiculate on 



their inner side. 



1. Elytra without scales, but with raised hairs, 

 visible if viewed sideways, and forming single 

 rows on each interstice. 



A. Anterior femora with a small tooth ; posterior 

 femora with a distinct tooth ; elytra bright 



blue. 



a. Striae of elytra narrow, interstices flat . . C. CYANIPENNIS, Germ. 



(sulcicollis, Piiyk. nee Gyll.) 



b. Striae of elytra broad, interstices convex. . C. CHALYB^US, Germ. 



B. Anterior femora without tooth; posterior 

 femora with a small tooth in female and with 



* This is the case with C. hirtulus only among our species. 



