116 S. A. ROHWER. 



Niteliopsis modestus n. sp. 



Male. — Length 4 mm. Very much like N. niger, but distinguished 

 by the following characters : — Clypeus with a broad obtuse median 

 tooth; the first recurrent nervure interstitial with the first tran. cu.; 

 and the more abundant silvery pile. The narrow apical margin of 

 the abdominal segments are testaceous. The posterior tibiae some- 

 times have a yellowish-white stripe posteriorly. Ocelli are in an 

 equilateral triangle. Wings hyaline, slightly dusky at the apex, 

 iridescent. 



Habitat.— Boulder, Colorado, June 1 and May 26, 1908 (S. 

 A. Rohwer) Found in company of N . niger, of which it may 

 be but a variety. 



Niteliopsis fossor n. sp. 



Female. — -Length 5 mm. Anterior margin of the clypeus with an 

 acute V-shaped tooth; middle carina strong. Head granular; frontal 

 carinae of the double U-shaped type, but the upper U is wanting. 

 Ocelli in an acute triangle; a slight indication of a median furrow from 

 anterior ocellus. Antennae slender, the third joint slightly longer than 

 the fourth. Prothorax rounded above almost as high as the dorsulum, 

 very slightly notched. Dorsulum and scutellum granular; scutellum 

 faintly impressed. Metanotum granular with a few striae at the base, 

 a distinct middle carina; metapleurae and posterior face striato-gran- 

 ular; posterior face with a triangular-shaped fovea. Venation as in 

 plenoculoides, except that the submedian cell is a little longer. Abdo- 

 men shining, finely punctured; pygidial area indistinct. Color black; 

 abdomen clear red; tarsi rufous; very sparsely clothed with silvery- 

 pile. Wings hyaline, apical margin slightly dusky, iridescent; venation 

 brown. 



Male. — Length 4.5 mm. The male is much like the female. The 

 third and fourth antennal joints with a spine beneath. The longitud- 

 inal carina is weaker than in the female; and there is a white stripe 

 on the posterior tibiae exteriorly. 



Habitat. — Boulder, Colorado, May 15, June 1, 190S; and 

 Rifle, Colorado, July 3, 1908 (S. A. Rohwer). 



This is much like foxii Viereck, but the third antennal joint 

 is not distinctly longer than the fourth; the fifth joint is not, 

 " shorter than the fourth." 



Oxybelus polygoni n. sp. 



Female. — Length 11 mm. width of thorax 4 mm. Very large and 

 robust. Clypeus with the usual truncate portion; clypeal carina not 

 very strong, but still distinct. Entire head below the ocelli closely, 

 rather finely punctured; vertex and occiput with larger more separate 



