ELATERIDAE. 185 



strongly from that genus. Our species (Elater dorsalis Say, Ul. 

 eleyans Fabr., M. amabilh Lee., M. comis Lee., and 31. livens 

 Lee.) were included in JNIonocrepidius, but arc distributed, with 

 some new ones, by Candcze, between the genus now under con- 

 sideration and .iEolus. 



The species of Mcgapenthes formerly placed in Elater have 

 been very properly sei)arated by Candcze. Tliere is not an entire 

 agreement between them in the form of the eo.xal plates. £1. 

 limhalis Ilerbst is also referred to this genus, though the coxal 

 plates are much less suddenly dilated internally; hardly more so 

 in fact than in Corymbitea selhiops. 



Group VII. — Ludii. 



This group has the front convex, Ijut not margined behind the 

 labrum ; the prosternal sutures concave outwards; the tarsi 

 simple, puliescent beneath, and the posterior coxal plates less 

 suddenly dilated internally, l)ut still distinctly angulated at the 

 middle of the hind margin, and strongly toothed at the insertion 

 of the thighs. The species are usually of large, though one 

 species, placed in Ludius, is of moderate size; it is the Oregon 

 L. tartareus formerly included in Elater. 



Our genera are two, thus distinguished, Crigmus Lee. having 

 been united with. Ludius. 



Mesosternum declivous, not proininunt. Ludius. 



Mesosternum protuberant. Orthostethus. 



To Orthostethus Lac. belongs Aphanobius infuscatus Germ., 

 a large brown species found in the Southern States. 



Sub-Tribe 2. — Coryml>itina. 



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

 scarcely dilated inwards, frecpiently not toothed over the insertion 

 of the thighs, with the hind margin nearly rectilinear. Li 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. Agriotks. 



Front flattened, margined ; mouth anterior ; 



Claws pectinate. ' Melanoti. 



Claws simple. Atiioi. 



