64 
times slightly broken; antennal fovea shallow, indistinct; mouth parts 
with rather long yellowish hairs; antennae very slender, slightly taper- 
ing, as long a-s abdomen, fourth joint a little longer than third; inter- 
costal nerve frequently interstitial with basal, nearly at right angles 
with costa; upper cell of hind wings exceeding lower; third cubital cell 
scarcely at all divaricating apically; stigma not very robust, tapering 
apically; sheath obtusely pointed, straight on upper edge, narrow; 
cerci as long as terminal joint of antennas, slender; head and thorax, 
particularly on lower side, with short, sericeous pile; claws rather 
minutely cleft, inner ray shortest. Color of head except palpi and 
sometimes lobes of clypeus, anterior margin of pronotum, band along 
center of mesonotuin, metanotum, metepisterna, basal plates, abdomen 
above, including sheath and cerci, and tips of posterior tibiae and their 
tarsi black; fore tarsi dusky; balance of thorax, venter of abdomen, 
and legs pale, ferruginous; the venter of abdomen more or less obscure 
with fuscous, sometimes very dark, approaching black; veins and stigma, 
including costa to base, dark brown. 
Two females from New Hampshire (Coll. Am. Ent. Soc.) and one each 
from Illinois and Washington (Coll. U. S. Nat. Mas.). 
30. Pteronus thoracicus Harrington. 
1893. Nematus thoracicus Harrington. Can. Ent., xxi, p. 58. 
1895. Nematus thoracicus Dyar. Trans. Am. Ent. Soc.,xxu, p. 307. 
Female. — Length 6 mm.; robust; clypeus deeply notched, lobes nar- 
row; walls of ocellar basin rounded, crest unbroken; antennal fovea 
shallow, circular; venation about normal; stigma broad, rounded on 
lower margin; sheath rather short and robust, regularly rounded at 
tip; claws evenly but not deeply notched. Color reddish yellow; an- 
tenna 1 , head except tip of clypeus and more or less of mouth parts, 
apical halt (sometimes all) of scutellum, metanotum, center of basal 
dorsal arcs of abdomen, and sheath black; tips of hind tibia' and the 
hind tarsi usually infuscated; veins, including stigma, brown; wings 
hyaline. 
Male. — Length 4.5 mm.; structurally in the main as in female; proci- 
dentia apparently nearly wanting. Color black; pronotum, teguhe, 
legs, and upper half of mesepimera and venter of abdomen yellowish 
ferruginous; hind tarsi infuscated. 
Eedescribed from the type specimen of female loaned by Mr. Har- 
rington and two bred specimens (male and female) received from H. G. 
Dyar, who reports the larvae (which he also describes) to feed singly on 
the lower surface of the leaves of Amelanchier canadensis. 
I have also examined five specimens, two from Washington and three 
from Mount Hood, Oreg. (Coll. Am. Ent. Soc). In some specimens the 
tergum is strongly infuscated and with more or less black on lobes of 
mesothorax. 
