88 
skeletonizing them at first and in their later stages eating entirely 
through. 
Mr. H. G. Dyar has described the larva of unicolor n. sp. (Trans. Am. 
Ent. Soc, xxii, p. 308), the food-plant being white birch, but in feed- 
ing habits agreeing with the European species. 
TABLE OF SrECIES. 
Females. 
Last dorsal arc of abdomen enormously developed. 
( laws bifid. 
Winga slightly infuscated basally: stigma brown basally; dorsum pale. 
1. unicolor n. sp. 
Wings clear; stigma pale; metanotnm and abdomen above black. 
2. mexicanus Cameron. 
Claws witb minute inner tooth 3. ponlanioidcs n. sp. 
Last dorsal air not unusually developed. 
Ocellar basin with distinct lateral wails and containing two small tubercles. 
4. pergandei n. sp. 
Ocellar basin with indistinct lateral walls and without tubercles. 
5. chloreus Norton 
1. Nematus unicolor new species. 
1895. yematu* unicolor Dyar. Trans. Am. Ent. Soc., xxii, p. 308. (Larva.) 
Female. — Length 7 mm.; rather robust, shining; clypeus deeply, 
rather narrowly notched, lobes large, rounded; ocellar basin scarcely 
present, deep furrow connecting anterior ocellus with antennal fovea; 
antennae slender, scarcely tapering, setaceous, about as long as head 
and thorax, third, fourth, and fifth joints subequal; intercostal nearly 
at right angles with costa, interstitial or nearly so; third cubital with 
sides parallel; posterior wings with outer veins of discal cells intersti- 
tial, or nearly so; stigma moderately elongate; sheath tapering, pointed, 
and with terminal abdominal segment enormously developed, repre- 
senting nearly hall' of abdomen; cerci very long, slender, almost as long 
as first joint of hind tarsi: claws rather large, inner ray very distinctly 
shorter than outer. Color uniformly reddish yellow; wing veins and 
stigma yellowish brown: antennae infuscated basally; ocelli very nar- 
rowly margined with black; basal plates more or less infuscated; wings 
hyaline, veins brown, stigma and costa yellow, former brown basally. 
Three females, one from Mount llood, Oreg. (Coll. Am. Ent. Soc), and 
two reared by Mr. II. G. Dyar from larva' on white birch collected in 
Green Valley, New'York (Coll. Dyar). 
2. Nematus mexicanus Cameron. 
1881. Nematus mexicanus Cameron. Trans. London Ent. Soc, p. 481. 
Female. — Livid, testaceous; face, sides and apex of abdomen above, and legs 
obscure livid yellow; antenna', metanotum, and back of abdomen except at apex, 
apex of bind tibia*, and tarsi black; anterior tibiae inclining to fuscous; wings 
clear byaline; costa and stigma whitish yellow; antennae sborter tban the abdo- 
