NORTH AMERICAN COLEOPTERA. 43 



species the 9 rostrum is longer and not so distinctly attenuate, but it is 

 not dilated at tip as are the species of the other sections. The antennae 

 did not seem to me to aflFord any safe guide, though it differs somewhat 

 in position and proportion ; other characters used will be referred to 

 when they occur, but none of them must be strictly and literally taken for 

 the species vary greatly, and a little variation one way or another may 

 occur without, however, conflicting with the character used to isolate an 

 allied species. 



The males may be recognized by the divided pygidium. 



Two genera are described as occurring in an fauna, the old genus 

 Apion of great extent and varying greatly while retaining for its species 

 a remarkable similarity of superficial appearance, and Podapian Riley 

 described on a single peculiar species. They are easily distinguished 

 by the tarsi. 



Tarsal joints subeqiial in width, not broader than long Apion. 



Tarsal joints widening to fourth joint; joints wider than long, tlie fourth much 

 the widest Podapion. 



APION Hbst. 



Of this genus five sections of very unequal extent are indicated and 

 may be recognized as follows : 



Slender; thorax narrow, cylindrical, as long as or longer than wide, not percepti- 

 bly wider ut base; sides usually equal, sometimes slightly dilated at middle; 

 elytra narrow, oval. Except in parallelum the species are not pubescent. 



Femur abruptly clavate, with an obtuse tubercle at inner side Section I. 



Femur not abruptly clavate and without tubercles Section II, 



More robust, usually pubescent, often densely so. Thorax never longer than wide, 

 usually transverse, rarely cylindric, usually depressed above. 



Rostrum tapering to tip, usually short and punctured Section HI. 



Rostrum not tapering to, but rather slightly enlarged or dilated at tip. 



Thorax more or less distinctly widening to base, sometimes cylindric, sides 



equal or arcuate, but never wider at middle than at base Section IV. 



Thorax usually depressed, widest at or behind middle and constricted at base. 

 Elytra ovate; thorax not cylindric Section V. 



Section I. 

 The species of this section are elongate, slender, shining black, with 

 none or but small humeri, and abruptly clavate femora (Plate i^, figs. 1 

 and 20) ; they are recognized at sight, and they may be determined as 



follows: 



Elytra without humeri angles. 



Eyes somewhat prominent, form very slender; thorax densely and coarseh' 



punctured, 2 mm erraticiim. 



Eyes less distinct; form more robust; thorax less densely and coarsely })unctur- 



ed, 2 mm ^ .... ol»!«oletiini. 



