78 



THE ORDER OF COLEOPTERA. 



c c. 



Anteuiipe not geniculate; anterior coxas contiguous; size medium. 



Ceruchus . 



B B. 



A A. 



[Fig 33] 



Body cylindrical ; head much narrower than the thorax, and prolonged into 

 a horn in the male, and tubercled in the female ; size medium. 



SiNODENDRON. 



Ligula broad, and filling the quadrangular notch of the mentum; antennsE 



not elbowed, first joint moderate; scutellum broad but indistinct, situated 



on the iDcduncle; elytra parallel and deeply furrowed. Size very large. 



Passaltjs . 



Lucanus contains three I^. American species ; the L. elapJins, a South- 

 ern species, the male varying in length from one and a half to more 



than two inches, with large 

 branching mandibles, larger 

 than the head and thorax ; L. 

 dama, our common innching 

 beetle, of a mahogany-brown 



\ color, and from an inch to an 

 inch and a half long; and the 

 L. placidus, an inch long, al- 

 most black, with the tooth of 

 the mandibles bifid at the tip. 

 JDorcus has but one generally 



Passalus coj^NUTUS:— a, larva; 6, pnpa; c, beetle; d, kuOWn SpCCicS, the JXiraUcJuS, 

 underside of .thoracic ioints, showine; atrophied hind leg • ■, -, ^ ^ 



of larva ; c, same eulaiged— after Kiley. of Say, brOWUlSh-blaCK, and 



eight or nine- tenths of an inch in length. The Platy cents quercus, four- 

 tenths of an inch long, of a brownish-black color, is a widely distributed, 

 but nowhere a common species. CerucJius piceus, dark brown, and half 

 an inch long, is occasionally found in considerable numbers in rotten 

 wood. Sinodendron is not known east of the Eocky Mountains. Fas- 

 salus cornutus, a large, oblong, depressed beetle, an inch and a quarter 

 long, of a shining black color, sometimes with a dark-reddish tint, and 

 with a short horn bent forwards, on the top of the head, is not an un- 

 common insect about the roots of decayed stumps and other similar 

 situations. The genus Passalus contains many species, most of which 

 inhabit S. America, but the P. cornutus is the only species found in the 

 United States. 



Meaning of generic terms : 



Lncanns — the stag, alluding to the large branching mandibles of some 

 of the males. 



Dorctis — the antelope. The males of some foreign species have large 

 toothed mandibles. 



Platycerus — having wide antennae. 



Ceruchus — bearing a horn. 



Sinodendron — injuring trees. 



Passalus — a 2)ost or peg, referring to the horn on the head of some 

 species. 



