132 MEMOIRS ON THE COLEOPTERA 



very obtuse but in some species are rendered more evident by 

 reason of a small feeble basal sinus adjoining. The mentum varies 

 somewhat in size, being generally though not always smaller than 

 in Pelecyphorus and allies; it is always seated upon a pronounced 

 gular pedestal, is more or less obtrapezoidal and with the usual 

 small median sinus at apex. The eyes are more or less feebly 

 sinuate anteriorly below the middle. The antennae are nearly of 

 the Pelecyphorus type but generally more gradually and feebly 

 enlarged through the two or three penultimate joints. The pro- 

 sternum is but seldom longitudinally impressed and descends more 

 rapidly upon the anterior margin of the mesosternum, the legs 

 varying in length and thickness, the tarsi moderate, generally 

 narrowly grooved and always having very short erect stiff hairs or 

 spinules beneath, the anterior tibiae strongly everted and acute or 

 spiniform externally at apex. The body is never very small and is 

 always glabrous or virtually so, except in the puncticollis group. 



The very numerous species and subspecies may be assigned to 

 the following seven clearly delimitable groups: 



Elytra with an acute marginal carina, or at least a well-marked subacute 

 ridge, through a more or less considerable part of their length; 

 mentum moderate, leaving a rather wide vacant space between its 

 sides and those of the buccal opening; body glabrous, except in the 

 puncticollis group 2 



Elytra without a sharply defined edge or carina at the sides, except 

 generally a very short one at the humeri; mentum generally similar, 

 though sometimes larger as in crassus; body completely glabrous 

 throughout 6 



2 Body wholly glabrous 3 



Body with short, sparse and erect hairs, sometimes longer and very 

 distinct on the elytra 5 



3 Pronotum with a distinct impression at the middle of the base, 

 involving the basal margin; upper surface of the_body very moder- 

 ately convex to nearly flat, the size always large Group I 



Pronotum without the narrow impression but frequently having a feeble 

 transverse impression parallel with the margin and separated there- 

 from by a slight transverse tumidity; upper surface much more 

 convex, the size never so large 4 



4 Elytra smooth, or each with three broad and feebly tumid discal 

 ridges, generally feebly sculptured; sides of the prothorax generally 

 rounded but occasionally angulate at the middle. [Stenomorpha 

 Sol. (pars)] Group 1 1 



Elytra with two distinct and strongly elevated discal costae on each and 

 occasionally a third, which latter tends to join the side margin 



