82 



THE ORDER OF COLEOPTERA. 



The following are the two priucipal genera : 



A. Club of autennne small with the plates of equal thickness ; size medium or above ; color dark me- 

 tallic green or purple, sometimes black Geotkyi'es, 7. 



A A. Club of antennio large and compact with the plates of unequal thickness ; size below medium ; 

 color brown BOT.r.ocEiius, :i. 



The G. sple7ididus, Fab., is our most common species, 

 usually about seven-tenths of an inch long, but varying 

 considerably in size, and varying also in color from dark 

 metallic green to puri)le. G. excrementi, Say, is a little 

 more than five-tenths of an inch in length, and of a 

 bronze-black color. G. opacus, Hald., is of a deep black 

 color, and varies in length from a little below to a little 

 above half an inch ; it is much rarer than the other two 

 species. The elytra are not furrowed like the others, but 

 only marked with lines of minute punctures. The Bolbo- 



G EOTRUPES : — 1, " 



beetle; 2, mundi- cevus farctus, Panzcr, is half an inch long, brownish-yel- 



bles; 3, antenna, J 7 J fe' J 



showing the larp low, witli the hiiid margin of the thorax, the sutural 



3-iointea subglo- 



bose club, and line, and the broad tips of the elytra black. B. Lazarus, 



bow the middle i n • t i 



joint is encased in Panzer, IS four-tenths of an inch long, and wholly oi a 



the ])recedino -r. .7' • o< 



after westwood. mahogauy-browu color. i>. Jilieorms, Say, thi-ee-tentlis 

 of an inch long, of the same color as the last, and distinguished by a 

 slender horn on the top of the head of the males, whilst the others have 

 only tul)ercles. The last species has been separated from the others 

 under the generic name of OdonUvus. It is also distinguished by having 

 the eyes completely divided by the lateral margins of the head. 



I 



Family XXIX. TROGIDiE. 



These insects are readily distinguished by their coarsely pitted thorax 

 and ridged elytra. The other characters given in the foregoing table 

 [ Fig. 37. ] are also very distinctive. They vary 



in size from more than a half to less 

 I-? ^Wdiy than a quarter of an inch in length, 

 and are of a uniform slate-black, or 

 brownish-black color. Their habits 

 are but little known, but they arc usu- 

 ally found in sandy situations, and 

 '^'uJ'i\ri'f7tJ'^^,-'-Tj'\ 'f^' ''■,P"P^i/' sometimes upon the carcasses of dead 



Ueetle ; a, c, j, leg, cervical plate, and maxilla, i 



with palpi of larva enlarged-after Kiley. auimals. Mr. Eilcy breeds TrOX pUS- 



tnJafus (Fig. 37.) from dead chickens. They are comparatively rare in- 

 sects. They are somewhat numerous in species, but are all included in 

 the genus Trox of Fabricius. 



