164 COLEOPTERA OF NORTH AMERICA. 



are gradually, but slightly, dilated internally; the tarsi in our 

 genera have the joints slightly inflated beneath, not furnished 

 with membranous lobes; the prosternal lobe is large; the an- 

 tennae are serrate in our genera. The species are found under 

 bark of dead trees. 



Antennal grooves occupying the whole, or nearly the whole, of the pro- 

 sternal suture ; 

 Third joint of the antennae smaller or narrower than the fourth. 



Agrypnus. 

 Third joint of the antenna? equal to, or larger, than the fourth. 



Adelocera. 

 Antennal grooves much abbreviated behind. Lacou. 



Of Agrypnus two species are found in Texas; Adelocera is 

 found in our whole territory, and Lacon in the Southern States 

 and Kansas. 



Tribe II.— CHALCOLEPIDIINI. 



The genus Chalcolepidius is represented by four species, one 

 (C. viridipilis) found in the Atlantic States, two in Arizona, and 

 one in southern California. They are very large insects, clothed 

 with depressed scales ; the mesosternum is protuberant, and en- 

 tirely connate with the metasternum, the suture being obliterated. 

 The antennas are pectinate in the male of C. viridipilis and sma- 

 ragdinus. The genus Alaus is represented by three species in 

 the Atlantic district ; it is commonly separated widely from Chal- 

 colepidius, but the protuberant mesosternum, closely connected 

 with the metasternum, with scarcely a trace of suture, indicates 

 its affinity with that genus. The form of body, too, is not unlike. 

 In both genera the coxal plates are gradually dilated inwards, 

 and strongly toothed at the insertion of the thighs ; the mandibles 

 have the tip entire, but not prolonged ; the front is concave, not 

 margined behind the labrum, but deflexeel ; the tarsi are not lobed 

 beneath, but very densely pubescent, and the claws are simple. 



Scutellum obcordate ; margin of elytra obsolete in front. Chalcolepidius. 

 Scutellum oval ; elytra strongly margined. Alaus. 



Tribe III— HEMIRHIPOTI. 



In this tribe, represented only by Hemirhijms fascicularis, the 

 front is concave, margined anteriorly; the mandibles are acute at 



