94 COLEOPTERA OF NORTH AMERICA. 



Monotonia, included in this family by Duval, should never have 

 had a place in it. 



This family divides into five sub-families, of which the second 

 is considered by Du Yal as forming a distinct family. The sole 

 character, the concealment of the maxillae by corneous plates, does 

 not appear of sufficient importance to warrant such a conclusion, 

 and I therefore follow the example of Erichson and Lacordaire 

 in considering it as a member of the present family. 



Anterior coxal cavities closed behind ; tarsi not lobed beneath, with the 



fourth joint small. Silvanid^e. 

 Anterior coxal cavities open behind ; 



Maxillae covered by corneous plates. Passandrid^;. 



Maxillae exposed. CccnjiD^;. 

 Anterior coxal cavities closed behind ; tarsi with the third joint lobed ; 



Fourth tarsal joint not smaller than the third. Hemipeplid^. 



Fourth tarsal joint very small. Telepuanid^e. 



Sub-Family I.— SYLVANIDAE. 



In this sub-family are contained but two genera, having the 

 genae prominent and acute; the antenna? with the first joint not 

 elongated, and the outer ones enlarged ; the anterior coxal cavi- 

 ties are broadly closed behind, and the tarsi, 5-jointed in both 

 sexes, have the fourth joint small. 



The genera are two in number, and the species, which are of 

 small size, are found under bark or in grain. 



Antennae with the joints 9 — 11 somewhat suddenly larger. Sylvanus. 

 Antennae with outer joints gradually enlarged. Nausibius. 



The type and only species of the last genus is N. dentatus, 

 having several large teeth on the sides of the thorax. It has 

 been diffused over the whole globe in articles of commerce. 



Sub-Family II.— PASSANDRIDAE. 



This sub-family is represented in the United States by a single 

 species, Catogenus rufus, of very variable size, found in the Mid- 

 dle, Southern, and Western States. It is dark-brown, elongate, 

 depressed ; the elytra are striate, and the antennas moderately 

 thick; the tarsi are 5-jointed in both sexes; the anterior coxal 

 cavities are open behind ; the genae are prolonged into plates 

 covering the maxillae. 



