NORTH AMERICAN COLEOPTERA. 19 



in the structure of the tarsi, which are all four-jointed. With the 

 PjBclerini tliey seem to possess very few characters in common, 

 differing from them even to a more marked degree in the tarsal and 

 antennal structures. 



On the other hand, they possess many characters not found in 

 either of the tribes under consideration ; as, for example, the minute 

 denticulation of the labrum in Eua^sthetus and the four-jointed tarsi, 

 as well as the small, very convex, coarsely granulated eyes, situated 

 very near the posterior angles of the head. 



From these considerations, therefore, it has been deemed best to 

 constitute of these three genera, a tribe equal in value to either the 

 Stenini or the Pfederini, and to be placed between them, with the 

 remark that the affinities which it exhibits are greater toward the 

 former than toward the latter. 



As the genus Stictocranius contains but one known species, which 

 has been sufficiently described by Dr. LeConte, it is proposed here 

 to limit the discussion to the genera Eua3sthetus and Edaphus, of 

 which the following tables and descriptions will serve approximately 

 to identify the species discovered thus far. The material at hand 

 forms a part of what is probably the most extensive American collec- 

 tion of these genera yet bi'ought together ; the Euajstheti were all taken 

 by Messrs. E. A. Schwarz and H. G. Hubbard, to whom I am indebted 

 for many acts of courtesy. 



EU^STHETUS ErAv. 



The species of this genus are very difficult to discriminate, and 

 especially so to satisfactorily tabulate, owing to a very remarkable 

 lack of salient characters. Those forms which appear to me worthy 

 of specific recognition may be classified as follows : — 



Elytral suture distinctly shorter than the pronotum. 

 Elytra strongly punctate ; disk polished throughout. 



Prothorax much broader than long ; sides of elytra strongly divergent 



posteriorly 1. tircvipeiiiiis. 



Prothorax but slightly wider than long ; sides of elytra feebly divergent. 



Large species 1.6 mm.; blackish-castaneous 2. piinctatlis. 



Very small species 1.0-1.2 mm.; very slender ; much paler, rufous or 



rufo-testaceous 3. florid ae. 



Elytra feebly punctate ; disk having a large area, about the inner apical 

 angles excessively minutely granulated and not polished. 

 Sides of elytra strongly divergent posteriorly ; border of fourth and fifth 



ventral segments strong 4. giniilis. 



Sides of elytra very feebly divergent posteriorly ; border of fourtli and 

 fifth ventral segments very feeble, nearly obsolete... 5. nilllldulus. 



