56 BULLETIN 45, UNITED STATES NATIONAL MUSEUM. 



tlie presence of the small oval cellule uuiting the humeral cellules. It 

 comes nearest to Goniozus Piirster. In the shape of the prostij^ma it 

 more resembles Peri senilis.''' 



Cameron does not appear to be acquainted with UupseneUa Westw., 

 which also has a closed radial cell and next to which I have i)laced it, 

 believino- it closely allied. 



Since the above was written I have received from Mr. G. C. ])avis, of 

 Agricultural College, Michigan, a remarkable male Bethylid, taken in 

 South Dakota, that agrees with Slerola in having a closed marginal 

 cell, but in other particulars differs so widely as to lead me to believe 

 it will yet prove quite distinct and form the type of a new genus. 



As Mr. Cameron, however, in his diagnosis, fails to define the palpal, 

 mandibular, and thoracic characteristics of ^Sierola, I am nnal>lo to de- 

 cide the question at present, and rather than run the risk of creating a 

 synonymn prefer to describe it doubtfully under this genus. The front 

 wing is represented on PI. iv, Fig. 2. 



(?) Sierola ambigua sp. nov. 

 (PI. IV, Fig. 2, S.) 



$ Length about 4.5'"". Black, j)olished, finely sericeous; sutures 

 of trochanters, extreme tips of all femora and tibiie and tarsi, except 

 last joint, honey-yellow; tibial spursl, 2, 2; claws with a small tooth 

 at base; wings subfuscous; palpi fuscous. 



The head is transverse, not quite as broad as the mesothorax between 

 the wings; ocelli 3, triangularly arranged; eyes oblong-oval, bare, reach- 

 ing not quite to the base of the mandibles ; antennte 13-jointed, filiform, 

 extending to baseof metathorax; scape subglobose, obliquely truncate 

 at tip; pedicel small, rounded; first flagellar Joint scarcely two-thirds 

 the length of second; the second joint h)nger than any other except 

 the last, the third and following to last joint very gradually shortened 

 the last a little longer than the second. Thorax shaped much as in 

 Epyris, except that the metanotum is smooth and polished instead of 

 rugose; the pronotum is large, trapezoidal, the collar anteriorly trans- 

 versely impressed ; the mesoscutum with two deep parapsidal furrows, 

 and with a longitudinal furrow ontheparapsides; scutellum with a trans- 

 verse furrow at base; metathorax subquadrate, the posterior angles 

 slightly rounded, margined at sides. Wings ample, subfuscous, the vena- 

 tion as in figure, brown-black or fuscous; the marginal cell closed and 

 not longer than the stigma; the second recurrent and second transverse 

 cubital veins partially visible as hyaline lines. Abdcmien lost. 



IIABITAT. — Brookings, S. Dak. 



Type in coll. Ash mead. 



Described from a single si)ecimen kindly given jne by Mr. G. C. 

 Davis. 



