NEW NORTH AMERICAN PSELAPHIDiE. 461 



impressed near the foveas, becoming completely obsolete anteriorly; vertex 

 gradually declivous between the antennas the declivity broadly biimpressed, 

 the impressions setigerous; lower edge bidentate in the middle, the teeth 

 slightly reflexed and with many erect setas on the lower surface, deeply ex- 

 cavated beneath between the antennas; clypeus broadly arcuate anteriorly, 

 sides feebly divergent posteriorly and nearly straight, angles slightly rounded* 

 not prominent, surface conical, edge not at all reflexed, having in the middle 

 an abrupt, small, strongly elevated tubercle at a considerable distance from 

 the anterior margin and rising just before the two superior teeth, exceedingly 

 minutely and sparsely setose; labrum broadly emarginate, angles prominent; 

 antennas slightly longer than the head and prothorax together, moderately 

 robust, very strongly clavate, basal joint more convex beneath, not otherwise 

 modified, as long as the next two together, second longer and more robust 

 th-in the third, eighth shortest, strongly transverse, ninth slightly longer 

 and nearly one-half wider than the eighth, transverse, tenth large, nearly 

 twice as wide as the ninth and very nearly as long as wide, sides parallel, 

 arcuate; eleventh distinctly narrower than the tenth, acumi«ate. Prothorax 

 slightly longer than wide; dorsal ridges and median sulcus almost completely 

 obsolete; median basal puncture small, round, nude, impressed; lateral 

 slightly larger, spongiose; lateral sulcations broadly impressed, feeble; lateral 

 basal tubercles minute; surface near the basal margin bifoveate at the sides, 

 not at all cariDate in the middle; disk convex, widest before the middle; 

 sides rather broadly rouuded, feebly sinuate toward base and apex; base 

 slightly more than three-fourths as wide as the disk, one-fourth wider than 

 the apex. Elytra fully as long as wide, convex; humeri slightly prominent 

 but not at all spinose. Abdomen with two long, parallel, prominent cusps at 

 base, distant by one-fifth the abdominal width. Legs rather long; femora 

 moderately robust; middle tibiae with an internal apical spur; posterior 

 feebly arcuate, with a terminal process. Length 1.7 mm. 



District of Columbia 2 (Mr. Henry Ulke). 



The female has the vertex strongly declivous, and thence 

 less strongly and continuously so over the surface of the clyp- 

 eus, which is finely, strongly and densely granulose; the 

 vertex is not excavated between the bases of the antennae, 

 each of which is inserted in a large lateral excavation. The 

 antennae are more slender, with the outer joints gradually 

 wider, the tenth transverse and but slightly larger than the 

 ninth. 



This species should also be placed near denticollis; these 

 three species belong to the nigricans group; the latter is, 

 however, distinguished by the unusual structure of the 



