51 
fourth; upper middle cell of hind wings short, quadrate, terminating 
at or usually within apex of lower cell; intercostal vein very slightly 
inclined, interstitial, or nearly so, with basal; second recurrent inter- 
stitial, or nearly so, with second transverse cubital vein; third cubital 
cell not strongly divaricating apically; stigma broad, rounded beneath, 
widest at center; sheath pointed, slightly excavated aboVe and rounded 
beneath; moderately robust; cerci robust, obtusely pointed; claws 
large, deeply cleft, rays snbequal. Color brownish black, including 
dorsum generally, coxae, femora except tips, tips of hind tibiae, all of 
hind tarsi, sheath, cerci, and more or less of apex of abdomen beneath; 
balance yellowish white, viz, inner and outer orbits, face below base 
of antenna}, pronotum except two or three dusky spots (sometimes 
wanting), teguhc, lat- 
eral edges of thorax and 
abdomen, and venter; 
palpi, more or less of ex- 
treme tips of fore tibiae, 
and commonly some of 
fore tarsi dusky; wings 
very faintly smoky; 
veins, including stigma, 
brown, costa pale on 
basal half. 
Male. — Length 7 mm. ; 
rather elongate; struc- 
turally as in female; 
procidentia as long as 
broad, narrow, taper- 
ing, squarely truncate 
or slightly emarginate 
at apex, constricted at 
base ; h y p o p y g i u m 
emarginate as viewed 
from end ; antenna} com - 
pressed laterally, stouter than in female. Color as in female, except 
that the inner orbits are black and the legs are dark reddish yellow, 
except bases of coxa} and rwsterior tarsi; abdomen reddish yellow 
beneath and dorsally over segments 2 and 3 and less on following ones; 
bases of all dorsal segments dark, terminal ones particularly so; hind 
tibia} very slightly infuscated, particularly at tips. 
Fig. 8. — Pteronus ventralis.: a, larva? feeding; b, larva, enlarged; 
cocoon, and d, adult — both enlarged (from Insect Life). 
Many bred specimens of both sexes. Washington, D. C. (Coll. IT. S. 
Nat. Mus.) 
A male and a female from Carbondale, 111. (Coll. Am. Ent. Soc), 
differ from the above in that the female has the upper middle cell of 
the hind wings exceeding the lower, and in the male the same termi- 
nates at aoex of lower. Three males from Michigan (Coll. U. S. Nat. 
