140 COLEOPTERA OF NORTH AMERICA. 



Tribe II.— MYRMECHIXEIVI. 



The two genera composing this tribe have been shifted about 

 from one part to another of the Clavicorn series, and seem 

 equally out of 'place in every position assigned to them. They 

 are very small inconspicuous insects, having a rather elongate 

 form, with the prothorax narrower than the elytra, which are a 

 little shorter than the abdomen, permitting the last dorsal seg- 

 ment to be i)artly visible. The front is transversely impressed 

 in Myrmechixenus, but not so in Ilypocoprus. The tarsi are 

 4-jointed, slender. 



Anteniiie with last four joints larger, elytra not truncate. 



Myrmechixenus. 

 Antennaj with last three joints larger, elytra truncate. Hypocoprus. 



Mi/rmechi:renus lathridioideff Crotch, has been found from 

 Washington southwards, introduced with green-house plants. 

 A species of Hypocoprus, probably identical Math the European 

 H. formiceto7-um, was collected in ant nests in Colorado by Mr. 

 Schwarz. 



Tribe III.— DIPI1YI.I.I1VI. 



This tribe contains a very small number of species, agreeing 

 in form with those of the first, but coarsely punctured, with less 

 fine and less .prostrate pubescence. The anterior coxal cavities 

 are closed. The tarsi are 5-jointed, but the fourth joint is small, 

 and the third prolonged beneath, forming a membranous lobe. 



The genus Diphyllus has but the tenth and eleventh joints of 

 the antennae enlarged, and has not yet occurred in our fauna. 

 Diplocoelus has the club of the antennae 3-jointed. 3IarginuH 

 Lee. has been united with Diplocoelus by Keitter, and in fact is 

 not sufficiently distinct to be retained. Vide Horn, Proc. Araer. 

 rhil. Soc. 1878, 606. 



Fam. XXVIII.— dermestidae. 



Mentum quadrate, usually corDeous; ligula simple; palpi 

 short, 8 -join ted. 



Maxillae witli the base exposed, with two lobes of vari- 

 able form; palpi small, slender, 4-jointcd. 



