1934] A Species of Epistenia from Colorado 229 
flagellum, pointed at apex, its basal joint blue; the long 
scape, shining greenish blue on outer side, is inserted very 
little above the mouth; head and thorax dull, with very 
dense coarse punctures, making a cancellate surface ; profile 
of thorax above practically straight; prothorax very large, 
swollen, parapsidal grooves very distinct, the mesonotum 
accordingly trilobed ; a black curved keel bounding axillary 
region anteriorly ; scutellum very large and convex, with no 
groove, the apex nipple-like; base of metathorax shining; 
tegulse small and black; wings hyaline with black veins; 
marginal vein less than half length of submarginal ; stigmal 
long and distinct, thickened at end ; postmarginal at least as 
long as marginal ; front femora robust, with a tooth beneath 
toward end; hind femora moderately stout; the large hind 
coxae rough with fine dense punctures, running in rows ; ab- 
domen nearly 5 mm. long, long-fusiform; the short first 
tergite smooth, shining green and rosy; second to fourth 
deep purple, with black hind margins, the surface covered 
with very large round punctures, not in rows, the dorsum 
not keeled; apical part of abdomen black and keeled, the 
ovipositor little exserted. The eyes have very long hairs. 
Type in Museum of Comparative Zoology, Cambridge, 
Mass. 
It may be that all the species of Epistenia are parasitic 
on Eumenidae. E. odyneri Ashmead (Psyche, VII, 1896, p. 
336) was bred by Dr. A. Davidson in California from Ody- 
nerus rufobasilaris Ashmead. It is quite a different species, 
the female 6 mm. long, strongly green, flagellum rufopiceous 
beneath, knees honey-yellow, tibiae and tarsi dark fuscous. 
