NORTH AMERICAN COLEOPTERA. 71 



The characters given above and in the table make this one of tlie 

 most sliarply defined species in our fauna. It associates very natu- 

 rally in focies and in the greater part of its characters with the three 

 species which precede, but is readily known by the presence of a 

 short, but distinct accessory spinule to the hind tibiie. 



One specimen. Cape San Lucas, I^ower California, in the LeConte 

 cabinet. 



A. cylilldriis Horn.— Elongate oval, moderately convex, ])ieeous or black, 

 moderately shining, legs reddish brown. Anteunje pale rufotestaceons. Head 

 moderately convex, punctulate, the punctnres at occiput coarser, at sides finer, 

 the middle of clypeus nearly smooth. Clyi^eus broadly emarginate and slightly 

 impressed at middle, an acvite denticle each side, the sides arcuate, gena?. moder- 

 ately prominent, obtuse. Thorax about one and a half times as wide as long, the 

 sides feebly arcuate, apex and base equal, hind angles obtuse, base arcuate at 

 middle, oblique each side near the hind angles, the basal marginal line distinct, 

 disc moderately convex, rather densely punctate, the punctures very little finer 

 to the front. Elytra elongate oval, the base as wide as thorax, humeri slightly 

 dentiform, surface deeply and broadly sulcate -striate, the strire indistinctly 

 coarsely punctured, the intervals acutely elevated. Mesosternum opaque, densely 

 and finely punctured, a polished carina between the coxa". Metasternum closely, 

 but indistinctly punctate at the sides. Abdomen feebly shining, sparsely punc- 

 tate at middle, more coarsely at the sides, the segments 2-5 crenate along their 

 anterior border. Anterior tibiae acutely tridentate externally, subcrcnate above. 

 Posterior femora sparsely punctate, the posterior marginal line entire, the tibia 

 without accessory spinule, the first tarsal joint not longer than the long spur. 

 Length .14-.16 inch ; 3.5-4 nun. 



The special characters which distinguish this species from those 

 most closely related are given briefly in the table, and need not be 

 repeated. 



Occurs from North Carolina to Florida. 



A. texaiius Harold. — .Similar in form to abdltiis, and very closely resembling 

 it, except in the following characters: Surface more shining. Thorax less closely 

 punctate posteriorly, the punctures becoming rapidly finer in front, so that the 

 disc is nearly smooth behind the apical margin. Elytra rather less deeply striate, 

 the striae crenately punctured, the intervals less convex than in nbditus and cre- 

 nate on the inner side by the punctures of the striae, the row of ])unctures on the 

 outer side of the intervals very fine and scarcely evident near the apex. Length 

 .16 inch ; 4 mm. 



This species so closely resembles ahditus in all essential charactei's 

 that one may suspect them to be merely variations, as may eventually 

 be the case with cyllndriciis and LeContei. 



Occurs in Texas and Arizona. 



