312 WILLIAM J. FOX. 



apical segment with a long narrow channel, its sides parallel; black, sparsely 

 clothed with pale hair. Wings snhhyaline, a cloud in the marginal cell fuscous, 

 nervures and stigma dark testaceous. Length 9 — 11 mm. 



% . — Anterior margin of the clypeus as in the female, except that the middle 

 tooth is by far the smallest; front with strong, close punctures; top of head more 

 closely punctured than in the female, likewise the cheeks, on the latter the punc- 

 tures are finest. Head from above distinctly narrowed behind, but hardly as 

 much as in Rileyi ; antennae rather long, reaching much beyond the collar, third 

 joint about one-quarter longer than the fourth, none of the joints dentate, the 

 seventh to tenth rather distinctly rounded beneath; dorsulum and scutellum 

 punctured like in the female, the striae on metanotum attaining the apex ; first 

 joint of medial tarsi somewhat bent and thickened towards the end; petiole of 

 abdomen distinctly longer than the first joint of the hind tarsi ; colored like the 

 female. Length 8 — 9 mm. 



Nevada. 



6. Peiiipliredon iiioriiatus Say. 



5 . — Anterior margin of the clypeus in the middle produced into a sharp tooth 

 or projection, which is somewhat reflexed ; front with strong, close punctures; 

 top of head with very strong scattered punctures, those on the upper part of 

 cheeks much closer and finer, on the lower part, however, they again become 

 strong and sparse. Head from above nearly quadrate, very slightly narrowed 

 behind ; third joint of antennte fully one-third longer than the fourth ; dorsulum 

 anteriorly strongly and closely punctured, on the remaining portion the punc- 

 tures become much larger and sparser; scutellum also very strongly punctured ; 

 enclosed space on metanotum laterally with several longitudinal ridges, medially 

 the ridges are irregular and form large fosste, the smooth space broadly lunulate, 

 the inner margin of which is produced into an angle in the middle, the posterior 

 face strongly rugose; petiole of abdomen distinctly longer than the hind coxse 

 and trochanters united, nearly as long as the first two joints of the hind tarsi. 

 Abdomen shining the last dorsal segment with a rather broad, shallow groove, 

 which is most distinct apically; black, clothed with long, pale hairs; sides of 

 face silvery. Wings hyaline, nervures and stigma testaceous. Length 7 — 8 mm. 



% . — .\nterior margin of the clypeus rather strongly emarginate in the raid- 

 die; front with strong, close punctures; top of head and cheeks punctured as in 

 the female. Head from above distinctly narrowed behind, fully twice as broad 

 as it is long in the middle, therefore it is very transverse ; third joint of antennae 

 but little longer than the fourth, joints 6-9 rather strongly rounded out beneath, 

 rugae in the enclosed space on metanotum longitudinal throughout, smooth 

 space as in the female, except that it is not quite so well marked ; first joint of 

 medial tarsi elongate, straight, not very much, though distinctly and gradually 

 thickened towards the apex. Abdomen shining, with very fine and distinct 

 punctures; colored like the female; the pubescence more dense; clypeus silvery. 

 Wings slightly fuscous on apical portion. Length 5 — 6 mm. 



Canada (Prov.), New York, New Jersey, Virginir, N. Carolina, 

 Illinois, Nevada. This and the following species belong to the Sec- 

 tion. Diphlebas Westwood, having both recurrent nervures received 

 by the first submarginal cell, and not to Cemonus Jurine as several 

 authors supposed. 



