1852.] 



45 



utrinque elevata submarginali notato, elytris fortiter seriatim punctatis. Long. 

 07. Platte River, Nebraska Territory : covers itselfwith a casing of mud like 

 the European species. The thorax is strongly margined, and has at the base 

 near the lateral margin a little interrupted elevated line. In one specimen the 

 the apex of the thorace is emarginate, but I can perceive no other difference. 



Syiiopsis of the Eucnemides of Temperate North America. 

 By John L. Le Conte, M. D. 



Although many entomologists consider that the small group of Coleopterous 

 insects, herein treated, constitute a peculiar family, I am under the necessity, 

 after very careful examination, of viewing them as a mere section of the exten- 

 sive natural family of Elateridae, and no more entitled to a distinct place in the 

 series, than any other group of genera in that family. 



The character which essentially distinguished the Elateridae from allied families, 

 as Erichson* has pointed out, is the looseness of the articulation bet ween the pro-and 

 meso-thorax. In order to allow of greater liberty of motion, the posterior margin 

 of the infixed portion of the prothorax is more or less dilated, or concave, so as 

 to slide over the opposing part of the messothorax. 



This character, although good in theory, is nevertheless sometimes difficult to 

 be seen, and is less developed in the Eucnemides than in Typical Elaters : yet I 

 have never failed to detect it, on close observation. In the genera Cebrio and 

 Cerophytum it is completely wanting : the former recedes too in the prominent 

 mandibles, and the latter in the posterior femora being inserted at the extremity 

 of the elongate trochanter, instead of at its base and side, as in Elateridae and 

 most other Coleoptera. Although I have not yet detected the affinities of this 

 difficult genus, I think there can be no doubt of the propriety of entirely excluding 

 it both from the Elateridae and Cebrionidae. 



The Buprestidae are distinguished from the Elateridae by the posterior margin 

 of the prothorax beneath, abutting directly against the mesothoracic segment. 

 More distinct characters will be found in the union of the first and second inferior 

 abdominal segments : the suture between them being visible only at the side : 

 a character of great constancy is found in the form of the eyes, which are strongly 

 transverse in all Buprestidae, while they are generally round in all Elateridae. In 

 order to include the Eucnemides with the other more typical groups, the Elate- 

 ridae may be thus defined. 



Coleoptera pentamera antennis serratis, mandibulis retractis^ octdis rotun- 

 datis ; prothorace iiifenie mesosternuTn superante ; acetabulis anticis ^;ar;i* 

 rotundatis, in prosterno sitis^ postice valde hientibus : coxis posticis laminatisy 

 trochanterUnts sinipUcibics ; abdomine ^-articulator segmeutis omnibus distmctis. 



According to the form of the sternum and front, this family may be divided 

 into several groups, of which the first and easiest, the Eucnemides, may be dis- 

 tinguished by the clypeus expanded in front of the antennae ; the labrum con- 

 cealed: the head strongly deflexed : the presternum not lobed in front. Our 

 native genera may be arranged as follows : 



A. Tarsi non laminiferi. 



a. Thorax marginatus, subtus non sulcatus. 



1. Palpi tenues, articulo ultimo vix crassiore. 



Pedes fortiter compressi, (antennae minus approximatae) Melasis Oliv. 

 Pedes tenues Tharops Lap. 



2. Palpi articulo ultimo dilatato, (saepius securi- 



formi'. . 



A. Caput sub oculis non sulcatum. 

 Laminae tectrices magnae intus sensim dilatatae . . Euryptychits. 

 Laminae tectrices intus subsubito dilatatae 



tarsi articulo 4^0 simplici ..... Epiphanis Esch. 



tarsi articulo 4to subtus breviter lobato . . Emathion Lap. 



Germar's Zeitschrift fiir Entomol. 2, 179, 



