NORTH AMERICAN COLEOPTERA. 25 



From the above very inadequate description it is impossible to 

 assign the sj)ecies a place. I was at one time disposed to consider the 

 species described further on as ovipennis synonymous, but at present 

 it would be certainly unwise to consider either that or any one of the 

 [)resent group identical with it. 



Group H. 



Scutellum small. Front convex, with at most very feeble traces 

 of tubercles. Anterior tibi?e normally tridentate, either obsoletely 

 or not at all serrulate above, the first joint of anterior tarsi as long 

 or longer than the second in all except stupidus. Posterior tibiae fim- 

 briate at apex with unequal spinules, the first joint of the tarsus 

 variable. Mesosternum simple or finely carinate in lentus. 



This group seems to be the most homogeneous of the present series. 

 The species are all more or less opaque, usually extremely finely pu- 

 bescent, the thorax always densely punctured ; they may be distin- 

 guished in the following manner : 



Elytral intervals flat, the striae fiuely or not punctured. 

 Mesosternum not carinate ; color black or piceous. 

 Elytral intervals without punctures or roughness, strife without punctures. 



opaciis. 

 Elytral intervals punctate and often submuricate. 

 Clypeus on each side distinctly angulate; first joint of posterior tarsus 



long lutuleiitiis. 



Clypeus on each side rounded ; first joint of posterior tarsus not longer 



than the next two $<»tiii>i<lus. 



Mesosternum finely carinate between the coxa?. 



Species small, ferruginous leiitiis. 



Elytral intervals very convex, the strise broad, with coarse, distant punctures; 

 mesosternum not carinate <lecipieiis. 



Speciniens of lutulentus occur with no angulation of the clypeus, 

 in this case the structure of the anterior and posterior tarsi, the larger 

 size and more prolonged elytra will distinguish them. 



A. opaous Lee— Oblong, moderately robust, black, opaque, a very narrow 

 sutural space shining. Antennae ferruginous, club darker. Head moderately 

 couvex, finely and rather densely punctured, front not tuberculate. Clypeus 

 emarginate at middle, the angles on each side well marked, but obtuse ; sides 

 arcuate, gense moderately prominent, but obtuse. Thorax convex, sides parallel 

 posteriorly arcuate in front, hind angles scarcely distinct, surface rather densely 

 and finely punctured except along the median line. Elytra not wider than the 

 thorax, humeri finely dentate, disc moderately deeply striate, the strife not dis- 

 tinctly punctured, intervals very fiat and opaque without trace of punctures or 

 lul)ercles. Body beneath coarsely, but not deeply punctured, the abdomen very 



TKANS. AMER. EXT. SOC. XIV. (4) FEUKUARV, 1SS7. 



