444 INSECTA. 



abundant in these Heteromera than in the following ones, which 

 enables them, even when transfixed and confined with a pin, 

 to live six months without food, a fact I have witnessed in 

 an Akis. 



Our first division of this family, which in the Linnaean sys- 

 tem forms the genus Tenebrio, is founded .on the presence 

 or absence of wings. 



Of those which are deprived of these organs, and in which 

 the elytra are generally soldered, some have the palpi almost 

 filiform, or terminated by a moderately dilated joint, and do 

 not form a distinctly securiform or triangular club. They 

 will compose a first tribe, that of the Pimeliari^e, so named 

 from the genus 



Pimelia, Fab., 



Which is the most numerous of the whole. 



Sometimes the mentum is more or less cordiform, the superior 

 margin either emarginated in the middle, and divided as it were 

 into two short and rounded lobes, or broadly emarginated or 

 widened. 



Here, the two last joints of the antennae, or the tenth or eleventh, 

 always distinct, sometimes unite to form an ovoid or pyriform body, 

 or are evidently separated from each other. The superior margin 

 of the mentum is rounded and emarginated in the middle, or as if 

 divided into two festoons. 



These have the anterior margin of the head almost straight or 

 projecting but slightly in the. middle, without a profound emargina- 

 tion for the reception of the mentum, and its lateral margin simply 

 and slightly dilated above the insertion of the antennae; the head 

 does not seem to be sensibly narrowed behind, nor widened and trun- 

 cated before. The thorax is not cordiform, deeply emarginated 

 before and truncated posteriorly. 



From these last, we may separate those in which the anterior mar- 

 gin of the head is straight, or nearly so, without any angular or 

 dentiform dilatation in the middle, in which the almost square and 

 moderate sized labrum is entirely exposed, the thorax is transversal, 

 and the abdomen extremely voluminous and inflated. 



Those, in which the body is more or less ovoid or oval, the thorax 

 narrower than the abdomen even at base, generally convex, without 

 acute prolongations at the posterior angles, and without a posterior 

 projection to the prsesternum, compose the subgenus properly called 



