ELATERIDAE. 1G7 



Drasterius is united by Duval with Cryptohypnus, but the 

 narrower prostemuin, with double sutures, distinguish it very 

 strongly from that genus. Our species {Elater dormlis Say, El. 

 elegans Fabr., 31. amabilis Lee, 31. comis Lee., and 31. livens 

 Lee.) were included by me in Monocrepidius, but are distri- 

 buted, with some new ones, by Caudeze, between the genus now 

 under consideration and JEolus. 



The species of Megapenthes were placed in Elater by me, but 

 very properly separated by Candeze. There is not an entire 

 agreement between them in the form of the coxal plates; thus, 

 the outer portion is much narrower in 31. stigmosus than in the 

 nearly allied 31. caprella. I would also include in this genus El. 

 limbalis Herbst, though the coxal plates are much less suddenly 

 dilated internally; hardly more so, in fact, than in Corymbites 

 eetkiops. 



Group IV.— Physorhini. 



The small number of species constituting this group have the 

 third joint of the tarsi furnished beneath with a membranous 

 lobe, the fourth being small, and received upon the fourth. The 

 front is very convex, its anterior margin rounded ; the posterior 

 coxal plates very narrow externally, suddenly dilated and strongly 

 toothed internally ; the claws are simple ; the mesosternum always 

 oblique; the prosternal sutures double, and in our genera exca- 

 vated in front. 



Coxal plates very suddenly, almost rectangularly, difated ; 



Second and third joints of antennae together equal to the fourth. 



Crepidotkitps. 



Third joint equal, or nearly equal, to the fourth. Bbachycrepis. 



Coxal plates obliquely, but very strongly, dilated; second and third joints 



of antennae together nearly equal to the fourth. Anchastps. 



To Crepidotritus belong Cryptohypnus cinereipennis Mann. 

 (Anchastus recedens Lee.) and C. tantillus Mann., both from 

 California. To Brachycrepis I would refer, besides the type B. 

 bicarinatus Lee, also Elater binus Say. ; the latter may, how- 

 ever, constitute a new genus, as the joints of the antennae are 

 carinate on the middle of the broad surface. 



Group V.— Monocrepidii, 



In this group the front is convex, margined in front; the first 

 joint of the antenna? is longer than usual; the prosternal sutures 



