302 [September 



ovate, apical segment slightly tinged with yellowish ; ovipositor very 

 short, rufous. Length 2\ lines; expanse of wings 4 lines. 

 ^a6.— Delaware. Dr. Thos. B. Wilson. 



17. Cryptus subargenteus, n. sp. 



Black, silvery--iericeous ; legs and abdomen, except 1st segment, rufous : 

 wings hyaline, iridescent. 



Female. — Black, clothed with a very fine silvery-sericeous pile, most 

 obvious on the face ; head rather large, transverse ; face short and 

 broad; eyes prominent; clypeus, vertex, occiput and cheeks, polished; 

 a spot on each mandible, and the palpi, whitish ; antennie three-fourths 

 the length of the body, slender, brown, tinged with rufous at base and 

 beneath. Thorax polished ; mesothorax with the dorsal lines well im- 

 pressed ; scutellum flat, polished ; metathorax pubescent, with the ele- 

 vated lines sharply defined, the central area large, elongate-subquadrate ; 

 tegulae pale yellowish. Wings hyaline, faintly tinged with fuscous, 

 iridescent ; nervures and stigma fuscous ; areolet sn'iall, 5-angular or 

 subquadrate. Legs slender, pale rufous, the four anterior coxge and 

 trochanters whitish, the posterior tibi<e and tarsi slightly dusky. Ab- 

 domen elongate, slender, strongly arcuated, shining; the 1st segment 

 long, linear, black, polished, slightly dilated at tip, with an obtuse tu- 

 bercle on each side of the middle ; 2nd and following segments together 

 oblong-ovate, subsericeous, rufous, faintly tinged with dusky at tip ; 

 ovipositor about as long as the basal segment of the abdomen, rufous, 

 valves blackish. Length 3 lines ; expanse of wings 5 lines. 



Ilab. — Pennsylvania. E. T. Cresson. 



Distinguished at once from the other species by the silvery face. 



18. Cryptus pusillus, n. sp. 



Black ; most of antennae, legs and 2nd segment of abdomen, rufous ; 1st seg- 

 ment of the latter striated ; wings subhyaline. 



Female. — Black, polished, slightly pubescent ; mandibles piceous, 

 palpi pale ; antenna; two-thirds the length of the body, rather short, 

 pale rufous, fuscous towards the tip. Thorax shining, minutely punc- 

 tured ; metathorax with the elevated lines sharply defined, the central 

 area rather large and triangular, and immediately behind it the pos- 

 terior face is abruptly and deeply excavated, the lateral tubercles promi- 

 nent; tegnlae pale rufous. Wings subhyaline, uniformly tinged with 

 pale rufous, slightly iridescent ; nervures and stigma fuscous, the latter 



