50 
6. Pteronus latifasciatus Cresson. 
1880. Nematus latifasciatus Cresson. Trans. Am. Ent, Soc., v1, p. 7. 
1886. Nematus latifasciatus Provancher. Add. Faun. Can. Hym., p. 24. 
, 1895. Nematus latifasciatus Dyar. Trans. Am. Ent. Soc., xxi, p. 304. 
Female.—Length 8 mm.; somewhat elongate, shining; clypeus shal- 
lowly and broadly emarginate, lobes short, broad; frontal crest and sides 
of pentagonal area strongly raised; antennal fovea large, oval, deeply 
excavated; antennie unusually slender and long, almost equaling thorax 
and abdomen in length, third and fourth joints subequal; intercostal 
oblique and almost its own length anterior to basal vein; upper cell of 
hind wings extending nearly one-fourth its length beyond lower; stigma 
narrow, elongate; sheath moderately robust, obtusely pointed, with 
straight upper margin; cerci very slender and nearly as long as second 
transverse cubital vein; claws very deeply notched, rays almost equal. 
Color of head, thorax with basal plates, four terminal segments of abdo- 
men dorsally and sheath, tips of hind femora, apical half of hind tibie, 
hind tarsi, and extreme bases of hind coxie brownish black; tips of ante- 
rior tarsi dusky; tips of clypeus, labrum, bases of mandibles, palpi, and 
basal half of hind tibize whitish; upper margin of pronotum, tegule, 
first four segments of abdomen dorsally except apex of fourth, all of 
venter, and legs yellowish ferruginous; wing veins, including costa, 
brown. 
One female, Cresson’s type. New Hampshire. (Coll. Am. Ent. Soe.) 
Mr. H. G. Dyar has characterized the larva (1. ¢.) from specimens 
found on birch. 
7. Pteronus ventralis Say. 
1824. Nematus ventralis Say. Keating’s Narr. Exp., 0, App., p. 315. 
1859. Nematus ventralis LeConte. Say, Ent.,u, p. 211. 
1861. Newatus ventralis Norton. Proc. Bost. Soc. Nat. Hist., vu, p. 159. 
1867. Nematus ventralis Norton. Trans. Am. Ent. Soce., 1, p.201. (Cat., ete., p. 63.) 
1869. Nematus ventralis Scudder. Ent. Corr. Harr., p. 270. 
1870. Nematus ventralis Riley. Am. Ent. and Bot., 1, p. 276. 
1873. Nematus ventralis Sylvester. Rept. U. 8. Dept. Agric., p. 254. 
1881. Nematus ventralis Thomas. 10th Rep. Ent. I11., 1880, p. 68. 
1885. Nematus ventralis Forbes. 14th Rep. Ent. ill., 1884, p. 117. 
1888. Nematus ventralis Howard. Insect Life, 1, p. 33, fig. 5. 
1889. Nematus ventralis Lugger. Bull. 9, Minn. Exper. Sta., p. 51. 
1889. Nematus ventralis Orcutt. Bull. 13, Dakota Exper. Sta., p. 13. 
1889. Nematus ventralis Bruner. Bull. 14, Nebr. Exper. Sta., p. 78. 
1890. Nematus ventralis Packard. Rep. U.S. Ent. Comm., v, pp. 524, 588. 
1891. Nematus ventralis Oreutt. Bull. 22, S. Dak. Exper. Sta. (March). 
1895. Nematus ventralis Dyar. Trans. Am. Ent. Soc., xx, p. 304. 
Female.—Length 8 mm.; only moderately robust; abdomen broadest 
beyond middle, shining; clypeus broadly and shallowly emarginate, 
lobes rounded; frontal crest large, indistinctly broken; ocellar basin 
well defined; antennal fovea deep, elongate, triangular; antenne slen- 
der, distinctly tapering, smooth, third joint usually slightly exceeding 
