20 NOKTH AMERICAN 



nearer the exterior than the interior edge, there is a small longitudinally 

 elongated spot of flavo-testaceous tint; surface deeply, closely, and evenly 

 punctate. Abdominal segments decreasing very gradually in width poste- 

 riorly, first much narrower than the contiguous elytra ; border very strong : 

 surface closely punctate ; transverse carinae unicuspid, cusp elongated. 

 Legs pale navo-testaceous ; femora clouded with fuscous toward tip, tarsi 

 slender, each joint shaded with fuscous at tip ; first joint of posterior equal 

 in length to the next three together. Under surface piceous-black, abdomen 

 distantly and finely punctulate, shining. 



Male. — Fifth ventral segment emarghiate in the middle third at apex, 

 emargination evenly rounded, five times as wide as deep, terminated by 

 rather well-developed teeth ; surface of segment impressed for a short dis- 

 tance anteriorly ; sixtli segment broadly and triangularly incised in its 

 middle half at apex, notch four times as broad as deep, angle slightly 

 rounded ; seventh broadly emarghiate at apex, longitudinally impressed 

 dorsally. 



Ft mule. — Unknown. 



Length 3.3 mm. 



Virginia, 1. 



This species differs from semicolon, which it resembles very greatly 

 in f'acies, in the structure of the antennal club ; in the present species 

 the tenth joint is long and cylindrical, and is equal in length to the 

 eleventh, while in semicolon the tenth joint is as broad as long, and 

 much shorter than the eleventh. It also differs very greatly in the 

 maxillary palpi, those of semicolon being very dark, especially toward 

 the tips, while in bilentigatus they are very pale flavate throughout. 

 These two characters are very striking and very singular when we 

 consider the very close resemblance in the general form of the body. 

 The legs in semicolon are also very much darker than in the unique 

 type of bilentigatus. 



Division B, 



In this division, by far the most extensive of the genus, the species 

 enjoy a comparativel)! great range of variation, not only in size but 

 in sculpture and structure of the various portions of the body. The 

 sculpture varies to such an extent from one form to another, is appa- 

 rently so constant and always so well marked and easily observed in 

 the individual species, that it has been assumed as the basis of primary 

 subdivision of the large number of forms here considered. The sub- 

 divisions are indicated by the following scheme : — 



Punctures joined into more or less tortuous channels in at least one portion 

 of the elytral surface, which channels exhibit an unmistakable spiral or 

 vortex arrangement, the spiral or vortex being complete or approximately 

 closed ; single punctures more or less isolated, may also exist at other parts 

 of the elytra a. 



