89 
men, almost glabrous, third joint a little shorter than fourth; vertex raised in 
center; frontal area a deep wide depression: antennal fovea large, longer than 
wide; clypeus deeply incised; palpi fuscous; wings lougish : second cubital cel- 
lule double the length of third, not angled where the recurrent ncrvures are received; 
third cellule a little widened at apex; the second recurrent nervure received a lit- 
tle in front of third transverse cubital; abdomen larger than the head and the 
thorax together, narrowed toward the apex, its last segment largely developed 
above; cerci long; ovipositor long, nearly half the length of the abdomen; the 
sheath at apex pilose; blotch small; cercilarge, white; claws bifid, spurs shortish. 
The vertex and mesonotum are very finely punctured; on the middle lobe of the 
latter is a central furrow; the extreme apex of the scutellum is black, and there is 
a narrow obscure black line down its center. 
Length 7 mm. 
Closely allied to the European X. lunnorrhoidalis Spin, and to the North Ameri- 
can X chlorous Norton. The occurrence of a Xcmatus so far south is of much inter- 
est, this being the first record of that northern genus in Central America. 
Habitat: Northern Sonora, Mexico (Morrison). 
The type of this species was not procurable and the original descrip- 
tion is quoted without alteration. 
3. Nematus pontanioides new species. 
Female. — Length & mm.; rather robust; clypeus very deeply and 
circularly emargiuate, lobes rounded; walls about ocellar basin and 
the frontal crest rounded, indistinct; vertex smooth, shining; antennal 
fovea broad, shallow; antennae not longer than head and thorax, 
slender, filiform, joints 3, 4, and 5 subequal; second recurrent received 
near second cubital: third cubital cell very elongate, three times as 
long as wide, narrow; stigma broad; sheath large, tapering, sharply 
acuminate, occupying with overlapping terminal dorsal sclerite nearly 
one-half of the abdomen; cerci very long, extremely slender, as long- 
as basal joint of hind tarsi; inner tooth of claw minute. Color honey 
yellow and dark brown • spot including ocelli and extending to antennae, 
anterior lobe of mesonotum, metanotum, abdomen except last segment 
and sheath, pleura, and pectus brown; antenna' brown, fulvous be- 
neath; femora inclined to brownish; coxse basally dark brown, almost 
black; wings nearly hyaline; veins yellowish brown; stigma yellowish 
hyaline, darker basally. 
One female. Mount Hood, Oreg. (Coll. Am. Ent. Soc.) 
In character of antennae and development of ovipositor and last 
segment of the abdomen, this species is closely allied to unicolor, but 
differs in the structure of the claws. The last segment of the abdo- 
men is enormously developed, and the long, sharply pointed sheath 
and long cerci may indicate a gall-making habit, whence the desig- 
nation pontanioides. The inner tooth of the claw is very minute and 
close to the tip, but in spite of this marked divergence from the char- 
acters of the claw of the genus the features of abdomen and ovipositor 
are so striking as not to permit of its being placed elsewhere. 
