168 NORTH AMERICAN 



Female. — Head much narrower-; interocular surface relatively broader ; 

 ocular lines more convergent ; sixth segment very obtusely and broadly 

 rounded behind. 



Length 4.6-4.8 mm. 



Michigan and Lake Superior (various points), 24 ; Middle States, 

 4; Canada, 2; Cambridge, Massachusetts, 2. 



A very common, widely diffused species ; the female is much more 

 robust than the male. 



14. A. annularis (Er.). — Form robust, sub-cylindrical. Pubescence 

 rather plentiful, somewhat long, sub-recumbent on the abdomen, more sparse 

 and erect on the remainder of the dorsal surface, cinereous ; entire body very 

 highly polished. Head moderate, twice as wide as long ; interocular surface 

 two-thirds wider than the eye, flat ; sulcations rather feeble, rounded, inter- 

 mediate surface much broader than the lateral portions, having at its base a 

 large impunctate area; punctures moderate in size, closely and polygonally 

 crowded ; ocular lines meeting at nearly three lengths in advance ; antennae 

 but slightly longer than the width of head, slender, piceous-brown through- 

 out, club robust ; third joint more than one-half longer than the fourth, 

 tenth slightly broader than long ; maxillary palpi very long and slender, 

 piceo-testaceous throughout, translucent. Prothorax widest just in advance 

 of the middle, where it is just perceptibly narrower than long ; sides thence 

 arcuate anteriorly, feebly sinuate posteriorly, slightly more convergent in the 

 former direction ; anterior margin shorter than the posterior, equally and 

 feebly arcuate ; surface rather finely, very closely, and somewhat confusedly 

 punctate, evenly convex, having in the middle of the disk five rather small 

 and irregular impunctate spots. Elytra at base very slightly wider than the 

 head ; sides parallel, equal in length to the width at base, strongly and 

 evenly arcuate ; together broadly, roundly, and strongly emarginate behind ; 

 suture nearly one-fourth longer than the prothorax ; surface of each elytron 

 very feebly tuberculate near its inner basal angle, punctures round, rather 

 small, very deeply impressed, nearly evenly distributed, generally distant by 

 slightly more than their own widths, interspaces very convex. Abdominal 

 segments decreasing scarcely perceptibly in width, first very slightly nar- 

 rower than the contiguous elytra, sub-cylindrical ; border obsolete, except 

 on the first segment, where it is very evident, especially toward the base ; 

 surface finely, closely, and evenly punctulate ; transverse carinae unicuspid. 

 Legs rather short and robust, femora black at the base, thence reddish- 

 testaceous to the middle, thence black to the tips ; tibiae blackish in the 

 basal half, piceous in the distal half; tarsi rather pale piceo-testaceous ; first 

 joint of posterior tarsi as long as next two together ; fourth joints very 

 strongly bilobed. 



Male. — Sixth ventral segment strongly sinuate at apex, sinus narrower' 

 and more acutely rounded than the apices, but slightly wider than deep, 

 evenly and narrowly rounded at the bottom ; teeth of seventh segment dis- 

 tinct and acute. 



Female. — Sixth segment broadly angulate at tip, angle broadly rounded. 



Length 5.0-5.5 mm. 



