AMERICAN COLEOPTERA. I"*"? 



On examiniug the under side of the head the usual setaB may be seen 

 at the middle of the mentum, one on each side and behind the base of 

 the mentum tooth and which may for convenience be called post-dental 

 set?e. In all the genera with one exception there will also be seen two 

 setigerous punctures at the side of the submentum immediately behind 

 the°angle of the mentum. In Polpochila and Agonoderm the two setae 

 are quke conspicuous, the inner one of each pair, however, larger than 

 the outer, but in the other genera the outer seta gradually becomes 

 more and more feeble so that it finally disappears or can only with great 

 difficulty be found. In Geopinus however there is but one seta on each 

 side and this is situated in the posterior angle of the mentum itself. 



The anterior tibiae are usually gradually dilated to apex and spinous 

 at tip externally, but in Geopinus the outer angle is expanded in a plate, 

 spinulose on its edge resembling in general form that of Glyptus. In 

 Nothopus the outer angle is more narrowly prolonged and rather deeply 

 sinuate above the tooth. Daptus has a thicker anterior tibia the outer 

 angle rounded, the posterior face rather closely beset with spinules as 

 in Phaleria, the fossorial habits of which it imitates. 



The following table will enable our genera to be recognized : 



Mandibles prominent, decussating. Body subpedunculate. 



Mandibles deeply stri.i;ose at tip. Anterior tibife decidedly fossorial. 



Eyes small. Mentum with a seta at hind angles CJeO|Uiius. 



Eyes large. Setse at sides of submentum Daptus. 



Mandibles acute at tip not strigose. Anterior tibia not foss.-rial. No seutellar stna. 



Head with deep arcuate impression each side Pogouotlaptus. 



Mandibles not prominent, at most feebly decussating. Body not peduncvilate. 



Outer apical angle of anterior tibite prolonged Motliopus. 



Outer apical angle of tibise not prolonged. 

 Mentum toothed. 

 Apical angles of joints 1—?. of anterior tarsi prolonged in spines. Eyes 



large. Hind angles of thorax obtuse or rounded Polpochila. 



Apical angles of joints of anterior tarsi not prolonged. Eyes small. Hmd 



angles of thorax sharply rectangular fralacaiiUlUS. 



Mentum not toothed. 



Posterior tarsi with the first joint a little longer than the second, outer 

 edge of middle tibire rather flat and with a double row of spinules 

 closely placed. 

 Eyes relatively small, distant beneath from the mouth ; elytra with 



numerous dorsal punctures Fiosoma. 



Eyes relatively large, very narrowly separated from the mouth ; elytra 



'with one dorsal puncture Agoiioderus. 



Posterior tarsi with the first joint nearly as long as the next three. 

 Middle tibiae with the spinules sparsely placed, in the male arcuate 

 and serrate on the inner side. 

 Eyes rather small; three series of elytral punctures.... Discoderus. 



' TKANS. AM. EXT. see. IX. '40) OCI OCKK, 1 SSI . 



