ELATERIDAE. 161 



mate grooves, which narrow the clypeus. The middle coxa? are 

 small, rounded, not angulated externally, and without trochantin; 

 the epimera of the mesothorax are very transverse. Eucnemis 

 possesses a feeble leaping power, which I have not observed in 

 our other genera, although several of them probably may exhibit 

 the same movement. The antenna? are frecpiently received in 

 grooves, which run sometimes along the under side of the pro- 

 thorax, sometimes along the prosternal suture ; the latter position 

 is assumed among our genera only in Microrhagus, and in that 

 the grooves are quite shallow. The claws have a broad tooth in 

 certain species of Fornax. 



The following table expresses the relation of genera : — 



Antenna! grooves at the margin of the thorax beneath ; 

 Joints of the tarsi 2 — 4 lobed beneath. Dendrocharis. 



Tarsi not lobed beneath ; 

 Antennae serrate. Eucnemis. 



Antenna? filiform. Fornax. 



Antenna! grooves usually wanting, never marginal ; 

 Prosternal sutures double, excavated. Microrhagus. 



Prosternal sutures single ; 

 Posterior coxal plates gradually but widely dilated internally ; 



Joints of antenna? 9 — 11 conspicuously longer. Phlegon. 



Joints of antennae 8 — 11 conspicuously longer. Epiphanis. 



Outer joints of antennas scarcely longer; infiexed part of prothorax 



feebly sulcate in front. Nematodes. 



Posterior coxal plates narrow, not dilated internally. Hylochares 



Posterior coxal plates narrow, very suddenly dilated internally. 



Anelastes. 



Phlegon Lap. is synonymous with Euryptychvs Lee. ; its geo- 

 graphical distribution is remarkable ; one species in Madagascar, 

 one in the Atlantic States, and one in California. Anelastes 

 contains two species, one on the Atlantic and another on the 

 Pacific slope. Epiphanis cornuia extends from Sitka to Canada, 

 The other genera are found only in the Atlantic district. Three 

 species which I refer to Nematodes are Euc. atropjqs Say, Ema- 

 thion penetrans Lee, and Euc. fr onto sus Say. At the time that 

 I wrote my revision of Elaterida? the genera were very obscurely 

 denned in the books, which will account for my failure to refer 

 these species to the proper genus. The six outer joints of the 

 antenna? are slightly enlarged in the male, as in Emathion, and 

 it is quite possible that the latter genus should be entirely sup*, 

 pressed. 

 11 



