AMERICAN COLT.OPTERA. 243 



wenerti of widely diverse tribes. T have observed souietliinc; similar 

 ID various lueinbers of the Staphylinidae, and more rarely in other 

 series of Coleoptera, but will have occasion to recur to this subject at 

 a later time, when I have studied the phenomena more closely. 



In all the species the lateral margin of tho prothorax is defies ed 

 near the front angles, so as to be visible from beneath for a short dis- 

 tance. The prosternal sutures are obliterated, the front coxal cavities 

 are small and not angulated at the outer side. 



The epipleural line is fine but distinct, and is distant from the 

 extreme margin of the elytra except in T. pMoeoporinus ; the meta- 

 thoracic epimera are in great part covered. 



Our species may therefore be arranged in the following groups, 

 which will perhaps be considered as distinct genera by those who are 

 inclined to subdivisions of that grade. 



I. — Eyes remote from the base of the niRndibles; third jointof maxillary palpi 

 elongnte-triangnlar, fourth joint aoicular distinct. 

 A. — Body slender, subcylindrical, very finely punctulate and pubescent; pro- 

 thorax not impressed, front angles not well-defined. 

 B. — Body strongly depressed, finely punctulate and pubescent. 



II. — Eyes extending to the base of the mandibles; third joint of maxillary 

 palpi turbinate truncate, fourth small, aeicular, distinct. Body broad 

 depressed, prothorax transverse, rounded, with two wide impressions and 

 dorsal ridge. Elytra with epipleural line strongly defined. 



III. — Eyes extending nearly to the base of the mandibles; third joint of 

 maxillary palpi ovate-elongate, last joint distinct or obsolete, according 

 to species. Body depressed, strongly punctured ; prothorax with a deep 

 lunate impression near the base, front angles not prominent. 



IV. — Eyes extending nearly to the base of the mandibles; third joint of 

 maxillary palpi turbinate, truncate at tip; fourth joint very small, dis- 

 tinct. Body slender, head, prothorax and elytra coarsely punctured; 

 prothorax with two parallel impressions, and intervening elevated dorsal 

 line. Elytra with the epipleural line not far from the extreme margin. 



V. — Eyes extending nearly to the baseof the mandibles; third jointof maxillary 

 palpi turbinate, last joint very small, frequently scarcely distinct. Body 

 depressed, punctured, pubescent; prothorax with impressions each side 

 of a dorsal elevated line. Epipleural line fine, distant from the extreme 

 margin. 



This last group contains the greater number of the species. They 

 may be easily separated by the form, sculpture and impressions of the 

 prothorax, but do not seem to present sufficient interest to occupy 

 attention at present. I therefore leave them for a future occasion or 

 anotlier student. 



