92 E. T. CRESSON. 



15. Pompilus cylindricus. 



Male. — Small, cylindrical, deep black; head, thorax and le<2js more 

 or less silvery-sericeous, especially bright on the face and metathorax; 

 anterior margin of the clypeus subtruncate or subarcuate; posterior 

 Figure 4. margin of the prothorax subangular ; metatho- 

 rax smooth and rounded, sometimes with a faint- 

 ly impressed central line; legs sparsely spinose ; 

 wings narrow, hyaline, the apex broadly mar- 

 gined with fuscous, marginal cell short, subtriangular, the third sub- 

 marginal cell petiolated (see Fig. 4) ; abdomen subsessile, subdepressed, 

 cylindrical, immaculate, sometimes faintly sericeous. Length 3 2 — 5 2 

 lines. 



Hah. — Pennsylvania, Illinois, Dakota Territory, Texas, (Coll. Am. 

 Ent. Soc); Virginia, (Coll. Mr. E. Norton.) 



Thirteen % specimens. This is one of our smallest species, easily 

 recognized by the narrow, cylindrical form of the body, and by the 

 petiolated third submarginal cell of the anterior wings. 



10. Pompilus arctus. 



Po»i2}i/us arctus, Cresson, Proc. Ent. Soc. Phil, iv, p. 453, % . 



Hah. — Colorado Territory, (Coll. Am. Ent. Soc.) 



One % specimen. Resembles cylindricus very much, but is distin- 



Figure 5. guished by the longer marginal cell, and by the 



|Subquadrate third submarginal cell, which is 



fully a third larger than the second (see Fig. 5). 



This species belongs to the subgenus Pompilus., 



and not to Ar/enia, as I stated in the original description. 



17. Pompilus virginiensis, n. sp. 



Male. — Long and slender, black, varied with a more or less brilliant 

 silvery pile, especially brilliant on the face, thorax, coxae and base of 

 the abdomen above ; anterior margin of the clypeus subtruncate or 

 slightly arcuate ; face, clypeus and mandibles silvery ; posterior mar- 

 gin of the prothorax angular; metathorax smooth and rounded, densely 

 silvery at the apex ; legs sparsely spinose ; wings hyaline, iridescent, 

 apical margin fuscous, marginal cell long and lanceolate, as usual, the 

 third submarginal cell much narrowed towards the marginal ; abdomen 

 elongate, subcylindrical, narrowed at base; the first, second and base 

 of the third segments covered with a fine silvery-sericeous pile, more 

 obvious in certain lights; sometimes the second, third and fourth seg- 

 ments have a silvery band at base. Ijcngth 3 — 5 lines. 



y/a^.— West Virginia, (Coll. Am. Ent. Soc. and Mr. E. Norton.) 



