82 GEO. H. HORN, M. D. 



closely placed at the declivous portion of the sides and more sparsely in a nar- 

 row region along the base, the median and anterior portion of the disc sparsely 

 finely punctured. Elytra as wide at base as the thorax, sides arcuate and slightly 

 wider posteriorly, humeri dentate, disc deeply striate, stride finely punctured, 

 intervals convex, but not carinate, ci-enate on their inner side, smooth. Mesos- 

 ternum opaque, densely punctured, the intercoxal carina short. Metasternum 

 sparsely punctate at sides. Abdomen coarsely punctured, less coarsely at middle, 

 almost cribrate at the sides. Anterior tibi?e tridentate externally, crenate above. 

 Posterior femora almost entirely smooth, the marginal line extending from knee 

 half way to base, the tibia with distinct accessory spinule, the first tarsal joint 

 a little longer than the long spur. Length .16-.18 inch ; 4-4.5 mm. 



AVith this species a series begins in Avhich stercorator may be taken 

 as the central form, and in which the species are very troublesome to 

 separate. Of all of them large series have been studied in the ma- 

 terial accumulated in the LeConte cabinet and my own with the 

 results given in the synoptic table, in which the distinctive charac- 

 ters have been given at unusual length. 



Occurs in southwestern Texas and probably also in Mexico. 



Specimens closely resembling the preceding species are in the 

 LeConte cabinet collected in Panama. The only appreciable differ- 

 ence is in the finer punctuation of the thorax of the Panama forms. 

 They are probably not specifically distinct. 



A. strigatus Say. —Oblong, parallel, moderately elongate and convex, pice- 

 ous black, shining; legs somewhat paler. Antennse rufotestaceous. Head mod- 

 erately convex, extremely finely sparsely punctured without trace of rugfe, the 

 occipital region with coarser punctures. Clypeus slightly impressed in front, 

 broadly feebly emarginate, broadly rounded each side, the sides oblique, slightly 

 arcuate, gense moderately prominent, subacute. Thorax nearly twice as wide as 

 long, slightly narrowed posteriorly, sides feebly arcuate, nearly straight, hind 

 angles very obtuse, base ai-cuate, the marginal line distinct, disc moderately con- 

 vex with coarse punctures sparsely placed in a narrow region along the base, 

 never closely at the sides, the punctures of the anterior and middle regions very 

 fine and sparse, almost entirely absent in front. Elytra as wide at base as the 

 thorax, humeri dentate, sides parallel, disc deeply striate, stria; finely punctured, 

 intervals feebly convex, crenate on both sides, smooth above. Mesosternum 

 opaque, densely punctured in front, not carinate between the coxae. Metasternum 

 smooth at middle, slightly rugose at the sides. Abdomen coarsely punctate at 

 sides, more finely at middle, the last two segments smooth at middle, the seg- 

 ments crenate in front. Anterior tibise tridentate externally, crenate above. 

 Posterior femora smooth, the marginal line extending two-thirds from knee to 

 base, the tibia with distinct accessory spinule, the first tarsal joint a little longer 

 than the long spur. Length .18-.20 inch ; 4. .5-5 mm. 



A specimen, which is presumed to be a male of this species, has 

 the anterior tibia somewhat more slender and the spur incurved. 

 The punctuation of the tliorax is also finer and the sides of the in- 

 tervals less crenate. The humeri are also less dentate. 



