348 A Preliminary Monograph of the 



Group IV. 



As far as ease of classification is concerned, the species of the 

 present group are by far the most interesting of the genus; they 

 are for the most part widely separated among themselves, 

 both in appearance and structural characters. The group 

 contains the largest and the smallest representatives of the 

 genus, and such forms as lithocharinus, ingens, and hrachyp- 

 terus stand out as markedly distinct types, perhaps connecting 

 the genus to its earlier and at present extinct allies. The 

 adopted classification follows: — 



Eyes small or at most moderate, the tempora not less than two-thirds 

 as long as the eye. 

 Pronotum coarsely and sparsely punctate, transverse. 

 Elytra longer than wide and about twice as long as the prothorax. 

 Elytral punctures denser; pronotal impressions very evident. 



23 diffusus 

 Elytral punctures sparser; pronotal impressions very feeble. 



24 lapsus 

 Elytra nearly as long as wide, much longer than the prothorax. 



25 pliloeoporinus 

 Elytra much shorter than wide and but very slightly longer than 



the prothorax 26 egregius 



Pronotum much more finely and densely punctate. 



Prothorax much wider than long, strongly rounded at the sides 

 anteriorly. 

 Elytra longer than wide; form depressed; extremely minutely, 

 densely punctate and pubescent; pronotum scarcely percep- 

 tibly impressed 27 litliocharinus 



Elytra quadrate or shorter, but distinctly longer than the pro- 

 thorax. 

 Pronotum very distinctly bi-impressed . 



The Impressions strongly subinterrupted in the middle of their 

 length; antennae short or moderate, not longer than the 

 head and prothorax. 



Elytra subquadrate 28 obliquus 



Elytra slightly wider than long. 



Legs and antennae deep black 29 sculptilis 



Legs rufous; antennae fuscous 30 difficilis 



The impressions not interrupted. 



Antennae long, conspicuously longer than the head and pro- 

 thorax; size large; head small 31 congener 



