The Sphegoidea of Nebraska 65 
Genus Bembidula Burmeister 
Bembidula ventralis (Say). 
1824. Monedula ventralis Say, Long’s Expedition, ii, Appendix, p. 336. 
1859. Monedula ventralis Say, Leconte edition, i, p. 227. 
1895. Bembidula ventralis Fox, Proceedings of the Academy of Nat- 
ural Sciences of Philadelphia, p. .353. 
Taken only in the northern and northwestern portions of the 
state. I have before me specimens from Carns, Glen, and War- 
bonnet canyon, taken during July and August on Melilotus, So- 
lidago, and Helianthus spp. 
Family PEMPHREDONIDAE 
KEY TO THE SUBFAMILIES 
Front wings with three cubital cells; antennae inserted far above the 
clypeus on or near the middle of the-face.............. PSENINAE 
Front wings with two cubital cells; antennae inserted close to the base of 
EL pay DEUS haae sta ac taltciots fess inid Vasa raid Slavevsts goatee PEMPHREDONINAE 
Subfamily PSENINAE 
KEY TO THE GENERA 
Cubital vein in hind wings originating beyond the transverse median 
nervure, the latter short and straight, perpendicular; submedian 
cell in front wings a little shorter than the median, the transverse 
median vein being not quite interstitial with the basal vein; sec- 
ond cubital cell usually much narrower above.............. Neofoxia 
Cubital vein in hind wings originating before the transverse median 
vein, the latter long and oblique or slightly bent, but not perpen- 
dicular. 
Second and third cubital cells each receiving a recurrent nervure, 
or the first recurrent nervure is interstitial with the first trans- 
verse cubital vein; head with a spine between the antennae; cly- 
peus anteriorly rimmed, and with a median sinus............... Psen 
~ Second cubital cell receiving both recurrent nervures, rarely with the 
first recurrent nervure interstitial with the first transverse cubital 
vein, or the second recurrent interstitial with the second transverse 
cubital vein; inner spur of hind tibiae dilated; metathorax with a 
median sulcus, the area at base striate or alveolate; petiole of ab- 
domen long, usually furrowed laterally; clypeus convex or sub- 
convex, separated, anteriorly more or less rounded and with a 
slight vein, but without a median sinus; labrum hidden..... Mimesa 
387 
