ELATERIDAE. 1G9 



To Orthostethus Lac. belongs Aphanobius infuscatus Germ., 

 a large brown species found in the Southern States. 



Sub-Tribe 2.— Corymtoitiiii. 



In this sub-tribe the coxal plates are gradually or sometimes 

 scarcely dilated inwards, frequently not toothed over the insertion 

 of the thighs, with the hind margin nearly rectilinear. In other 

 characters there are found great differences between the groups ; 

 the prosternal sutures are frequently straight and simple, and the 

 prosternal lobe is sometimes entirely wanting. The claws are 

 pectinate in certain genera. 



The following groups are represented in our fauna : — 



Front convex ; mouth inferior. Agkiotes. 

 Front flattened, margined ; mouth anterior ; 



Claws pectinate. Melanoti. 



Claws simple. Athoi. 

 Front flattened, not margined ; mouth anterior ; 



Mesosternum declivous. Corymbites. 



Mesosternum protuberant. Melanactes. 



Group I. — Agriotes. 



This group, composed of species of moderate or small size, is 

 distinguished by the convex front, the edge of which is higher 

 than the labrum ; the mouth is situated on the inferior surface of 

 the head, and is applied to the presternum iu repose ; the latter 

 is lobed in front; the sutures are double, either concave outwards 

 or nearly straight, somewhat excavated in front ; the antenna? are 

 slender, scarcely serrate, and the first joint is a little longer than 

 usual ; the coxal plates are but slightly broader internally, although 

 sometimes almost suddenly dilated ; the tooth at the insertion of 

 the thighs is large. 



Our genera are : — 



Front truncate, not margined behind the labrum, although higher than it ; 

 claws simple ; 



Margin of prothorax defiexed in front. Agriotes. 



Margin of prothorax straight. Dolopius. 

 Front margined ; 



Claws and tarsi simple. Betarmon. 



Claws pectinate, tarsi slightly lobed. Adrastps. 



To Dolopius, as here defined, belong D. macer Lee, pauper 

 Lee, and subustus Lee. ; to Betarmon belongs only Elater bi<jc- 



