56 BULLETIN 45, UNITED STATES NATIONAL MUSEUM. 



the presence of the small oval cellule imitiug the humeral cellules. It 

 comes nearest to (ioniozus Fiirster. In the shape of the prostijjjma it 

 more resembles Perlstmusy 



Oamertm does not appear to be acquainted with Eupsenella Westw., 

 which also has a closed radial (iell and next to which 1 have placed it, 

 believing; it closely allied. 



Since the above was written I have received from Mr. G. C. Davis, of 

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

 South Dakota, that agrees with Sierola 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 i)alpal, 

 mandibular, and thora(;ic characteristics of Sierola, I am unable 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, polished, flnelj' sericeous; sutures 

 of trochanters, extreme tips of all femora and tibite 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; antennie 13-jointed, filiform, 

 extending to baseof metathorax; scape subglobose, obliquely truncate 

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

 the len^fth of second; the second joint longer than any other except 

 the last, the third and following to last joint verj^ gradually shortened 

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

 Epyris, except that the metauotum 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 ontheiiarapsides; 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 i^Jirtially visible as hyaline lines. Abdomen lost. 



Habitat. — Brookings, S. Dak. . TTT 



Type in coll. Ashmead. 



Described from a single sjMicimen kindly given me by Mr. G. C. 

 Davis. * 



