102 NORTH AMEUICAN 



tions very large and prominent, strongly angulate externally; connecting 

 ridge feelily arcuate anteriorly and somewhat strongly depressed in the mid- 

 dle ; antennae two-fifths longer than the head, somewhat slender, club short 

 and rather robust, joints three to eight moniliform, eighth very slightly 

 shorter than the seventh, and very slightly transverse, ninth as long as the 

 eighth, nearly twice as wide as long, tenth one-half longer and two-thirds 

 wider than the ninth, eleventh as wide as long, very slightly wider than the 

 tenth, abruptly truncate anteriorly, and acutely produced at the immediate 

 vertex. Prothorax widest just in advance of the middle, where it is as wide 

 as the head, and scarcely as wide as long ; sides thence very slightly con- 

 vergent and feebly arcuate for a short distance, and then abruptly very 

 strongly convergent and feebly sinuate anteriorly, convergent, straight, and 

 feebly undulated posteriorly ; apex very slightly less than one-half as long 

 as the pronotal width, and two-thirds as long as the base ; disk rather 

 strongly convex, polished, very minutely and sparsely punctulate; having 

 a small, elongated puncture just before the middle, and a broadly dilated 

 foveate impression at about one-fourth the length from the base, which is 

 connected with the deep, circular, spongy-pubescent lateral foveae just be- 

 hind the middle by narrow, arcuate, well-markeil grooves. Elytra at base 

 as wide as the head ; sides moderately divergent posteriorly and rather 

 strongly arcuate ; disk just visibly longer than wide, rather strongly convex, 

 shining, not punctate ; sutural striae strong, close, nearly straight, lateral 

 obsolete, except in the basal third, where they are broadly and feebly im- 

 pressed ; humeri rather prominent. Abdomen at base very slightly narrower 

 than the elytra ; sides slightly divergent posteriorly and straight ; border 

 strong, slightly inclined; surface broadly convex, polished, very minutely 

 and sparsely punctulate ; first three dorsals exactly equal in length; first 

 two witli two rather close, strongly divergent basal carinae, those of the first 

 longer and stronger than those of the second. Legs long, rather slender ; 

 middle femora of male swollen. Length 1.5 mm. 



Washington, District of Columbia, 3. 



The description is taken from a male in order to better compare it 

 with difflcilis to which it is extremely closely allied. It ditiers in the 

 shorter and much more robust terminal joint of the maxillary pali)i, 

 in its sligiilly more robust form of body, especially behind, and in its 

 distinctly shorter and broader abdomen, sides of the elytra more 

 divergent and arcuate, and in the sexual characters. The apical edge 

 of the third ventral segment in (lijfrrih's is comi)letely entire without 

 any trace of irregularity, while in congener it is produced for a short 

 distance in the midiUe ; the fourth segment is relatively shorter and 

 has a distinct median tubercle; the sixth segment is broader and 

 shorter and nion.' broadly rounded anteriorly than in difficills. 



"NVe have here an instance of cases which frequently arise in syste- 

 matic investigations of this nature, and which are extremely puzzling. 

 After cai'eful scrutiny of tiie general form of the insect we are almost 

 morally convinced of the identity of two si)ecimens, but upon more 



