420 COLEOPTERA OF NORTH AMERICA. 



form; the lobes of the maxillae are not prolonged; the claws of 

 the tarsi are usually cleft to the base ; the upper part is not ser- 

 rate iu our genera, and the under part is usually equal in length 

 to the upper one : in Phodaga, Eupompha, Tegrodera, the under 

 portion is connate with the upper one, and only half as long. 

 Four natural groups appear to exist among our genera : — 



Vertex not elevated ; 



2d joint of antennse long. Macrobases. 



3d jokit of antennae much longer than the 2d. Canthakides. 

 Vertex elevated ; 2d joint of antennae small ; 



Mandibles obtuse. Eupompike. 



Mandibles emarginate. PnoDAGiE. 



Groui) I. — Macrobases. 



The eyes are strongly transverse and broadly emarginate ; the 

 antennae are inserted in front of the eyes; the first joint is usually 

 much elongated, esi)ecially in the males, frequently compressed 

 and bent in that sex; the second joint is larger in the males than 

 iu the females, and is generally longer than the third, sometimes 

 much longer, but in several species the second is not longer 

 than tlie third ; the vertex is not elevated ; the last joint of the 

 maxillary palpi is triangular and obliquely truncate ; the mandi- 

 bles are thick and obtuse, with a small tooth near the apex. The 

 anterior thighs have a sericeous spot of hair on the under surface. 

 The spurs of the hind tibiae are always slender, and the divisions 

 of the claws equal ; the tarsi are pubescent beneath. 



One genus, Macrobasis, occurs in our fauna, containing a 

 moderate number of species, found in the Atlantic and Central 

 districts; none have as yet occurred in the Pacific region. 



Group II. — Cantharides. 



The eyes arc transverse and broadly emarginate ; the antennae 

 arc inserted in front of the eyes, with the second joint much 

 shorter than the third, and except in Pleuroporapha, very small ; 

 they are sometimes filiform, sometimes with the outer joints larger 

 and rounded ; the vertex is not elevated ; the last joint of the 

 maxillary palpi is broadly rounded at tip ; the mandibles are 

 truncate, and have a small tooth near the apex; the spurs of the 

 hind tibiae are variable in form ; the divisions of the claws of the 

 tarsi are usually equal ; in Calospasta and Tegrodera, the under 



