Fossorial Ili/mcnoptera of North America. 399 



covered with a net-work of shallow fossulets; pedicel laterally 

 grooved; legs black, coarsely, thinly long sericeous; tarsi pale, uni- 

 formly whitish testaceous, a little fuscous towards ungues; posterior 

 edge of the abdominal segment finely hirsute. 



Length of the body, .12 inch. 



Western Virginia, Ridings, (Coll. Ent. Soc. Phil.). 



$ . Head cubical, angular at the sides, black, polished ; ocelli of the 

 usual distance apart, arranged in an equilateral triangle; punctures 

 sparse, shallow, surface not lineated, highly polished, slightly lineated 

 between the ocelli and the insertion of the antennae, which areslightlv 

 olavate, black, but rather broad ; v-shaped, mesially cleft, ridge between 

 the insertion of antennae unusually prominent; hairs of lab rum coarse 

 setose, arranged in a semicircle, gradually shortening on the sides ; 

 mesoseutum polished, with sparse shallow punctures, as is the scutel- 

 lum ; meta-scutellum unequally and indistinctly punctostriated. En- 

 closure of propodeum equilaterally triangular, with four rugae on each 

 side of the lozenge-shaped mesial furrow, sides posteriorly curved, 

 with a coarse, distinct net-work of fossulets, tegulae externally testa- 

 ceous, wings clear, nervures dark piceous; legs very uniformly brown, 

 fore tarsi testaceous-brown, middle tarsi darker; hind tarsi much 

 darker, concolorous with the tibiae; while the whole body is coarsely 

 sericeous, the legs are finely so. Abdomen smooth, slightly seri- 

 ceous, sutures well impressed, wings being slightly emarginate, pe- 

 dicel as long as the depth, but not the breadth of the abdomen, grooved 

 laterally above and beneath, highly polished. Tips narrow, compressed, 

 three times as long as broad, rather deeply grooved. 



Length of body, .28 inch. 



Penn., (Coll. Ent. Soc. Phil.). New York, (Norton). 



This species represents Psen ater Fabr. of Europe, resembling it in 

 its entirely black body and dark extremities; its silvery sericeous front; 

 the want of striae on the vertex of the head, and on the thorax, its 

 coarsely rugose propodeum, the peculiar grooved abdominal tip, the 

 dark tarsi and antennae, and the large v-shaped prominence between 

 the origin of the antennae, wherein it resembles Cerceris, will suffi- 

 ciently distinguish it. 



Psen niger, n. sp. 



% . Head transversely oblong; sides rounded posteriorly; vertex 

 slightly elevated, ocelli arranged in a low triangle; eyes prominent; 

 vertex coarsely and densely punctate, scarcely polished ; front densely 

 pubescent from just above the insertion of the antennae to the edge 



