206 COLEOPTERA OF NORTH AMERICA. 



nian Anobimn cornutum Lee. ; the mandibles of the male are 

 armed at the base, each with a long slender horn, ascending and 

 curving inwards, so as to meet its fellow at the tip. To Philoxy- 

 lon belong Anobium conveocifrons Mels., and A. punctulalum 

 Lee. 



Tribe II.— PTILININI. 



But one genus, Ptilinus, of accurate cylindrical form, represents 

 this tribe. The head is deflexed, less retractile than in the pre- 

 ceding groups ; the eyes are small, rounded, and distant from the 

 thorax in the female, but larger in the male ; the antennae are 

 serrate in the female, branched in the male, and 11-jointed. The 

 last joint of the palpi is oval. The thorax is convex, rounded 

 in front, protecting the head, and granulate with small tubercles 

 towards the apex ; it is not excavated beneath, and the pro- 

 sternum is moderately developed in front of the coxa?, which are 

 large and contiguous. The plates of the hind coxa? are exceed- 

 ingly narrow. The legs are moderately retractile, and the first 

 joint of the tarsi is longer than the second. The genus is repre- 

 sented on both coasts of our country ; it approaches closely in 

 form certain members of the tribe of the next sub-family, and 

 establishes a transition between the two. A slight relation with 

 Melasis of the sub-family Eucnemidae is likewise quite obvious. 



Sub-Family IIL—BOSTRICHLDAE. 



The insects of this sub-family are elongate in form ; the head 

 is usually deflexed, and protected by the thorax, which is then 

 hood-like in form ; in one tribe, Psoiui, it is prominent, and not 

 covered. The mentum is usually small, but in Psoini is large and 

 transverse. The antennae are distant, and inserted immediately 

 in front of the eyes, upon, or under the frontal margin, and the 

 three outer joints are always larger. The eyes are small, convex, 

 rounded, and distant from the prothorax. The pronotum is not 

 separated from the flanks by a marginal line, except in the first 

 tribe. The anterior coxae are large, globose or sub-conical ; the 

 hind coxae are not sulcate behind, and project at the inner part ; 

 the spurs of the middle and hind tibiae are distinct, and the ante- 

 rior tibia? are terminated by one long spur, and usually serrate ; 

 the trochanters are short ; the first joint of the tarsi is very short, 



