[55] NORTH AMERICAN COLEOPTEKA. 211 



The color may vary somewhat from immaturity, both the 

 head and prothorax being sometimes paler. The single 

 specimen upon which this statement is based differs, how- 

 ever, in its slightly denser elytral punctuation; it is prob- 

 ably a female, the sixth segment being entire, narrowly 

 rounded at apex; the second segment is entire, but the 

 third has the two foveae as described in the male. 



The present species belongs near A. politics Sharp, which 

 it resembles greatly in sexual characters; from nactus Horn, 

 it differs in color and in its much more elongate prothorax 

 and elytra. 



The genus Ababactus differs from Hesperobium not only 

 in the structure of the labrum, — which allies it more closely 

 with Cryptobium, — and tarsi, as remarked by Dr. Sharp, 

 but also in the complete absence of the large basal carina 

 of the first ventral segment, which is such a prominent 

 feature of Hesperobium. The two post-ocular annular 

 punctures are well developed in Ababactus, and are com- 

 pletely absent in Cryptobium fracticorne Payk. 



LENA n- ge»- (Piedeiiui.) 



Body robust, depressed; head rather large; antennas short and robust; 

 labium rather short, broadly rounded, with a simple median sinnalion about 

 twice as wide as deep with no trace of denticulation or caiina; third joint of 

 labial palpi very minute and slender; third joint of maxillary palpi much 

 longer than the second, slender, fusiform, obtusely pointed at tip; fourth 

 excessively miuute, slender, subulate; eyes moderate, coarsely granulate. 

 Prothorax subquadrate, narrowed toward base, shorter than the elytra. In- 

 termediate and posterior tarsi rather slender, cylindrical; first joint of the 

 latter as long as the next two together, distinctly longer than the fifth; fourth 

 short, very slightly dilated, oblique at apex; anterior tarsi robust and spon- 

 gy-pubescent beneatb, very feebly dilated. Integuments rugulose, coarsi ly 

 punctate, shining. Neck rather slender; gular sutures well separated. 



This genus belongs near Medon, but is easily distin- 

 guished from it by a peculiar and complicated modification 

 of the pronotal hypomera, the surface being deeply grooved 

 opposite the base of the cox;<> and the acute dividing line 



