66 
and distinctly excavated; lateral walls rounded; frontal crest strongly 
developed, divided by narrow depressed line at middle; antennal fovea 
deep; antenne slender, strongly tapering, joints 4 and 5 subequal; 
venation normal; sheath narrow, tapering to rounded tip; claws deeply 
and evenly notched. Color of antenn, large spot including ocelli and 
extending over vertex, dorsum of thorax, and abdomen black; posterior 
tibiz darker at tips, with tarsi brown; sheath brown; veins brown, 
stigma scarcely paler; face, orbits, pronotum, tegule, entire venter, 
with lateral edges of dorsum of abdomen, pallid or resinous. 
Male.—Length 5 mm.; slender; antenne not much stouter than in 
female; procidentia short, narrow, projecting about its own width. 
Color as in female, except that the antenne are fulvous beneath and 
the pectus is strongly infuscated. 
Eleven females and five males (Coll. Cornell Univ.), labeled ‘+ Lot 85, 
sub. 965,” dated May to July, 1890. 
33. Pteronus trilineatus Norton. 
1867. Nematus trilineatus Norton. ‘Trans. Am. Ent. Soc., 1, p. 215. (Cat., etc., 
Dendidis) 
1872. Nematus trilineatus Norton. Trans. Am. Ent. Soc., Iv, p. 79. 
1877. Nematus trilineatus Glover. Rept. U. S. Dept. Agric., p. 92. 
1880. Nematus similaris Norton. Rept. Ent. U.S. Dept. Agric. 1879, p. 224, Pl 
D1, fig 
1881. Nematus trilineatus Thomas. 10th Rept. Ent. Ill., 1880, p. 68. 
1885. Nematus robinia Forbes. 14th Rept. State Ent. Ill., 1884, p. 116, Pl. 12, 
fig. 5. 
1886. Nematus similaris Harrington. Can. Ent., xviii, p. 39. 
1886. Nematus similaris Provancher. Add. Faun. Can. Hym., p. 24. 
1890. Nematus similaris Packard. Rept. U. 8. Ent. Comm., v, p. 369, fig. 136. 
1890. Nematus robiniw Packard. Rept. U. 8. Ent. Comm., v, p. 370. 
1895. Nematus similaris Dyar. Trans. Am. Ent. Soc., xx1I, p. 301 (larva). 
Female.—Length 6.5 to 7 mm.; moderately robust, shining; clypeus 
broadly, circularly, but deeply emarginate, lobes large, triangular; 
frontal crest and sides of ocellar basin distinctly defined, former un- 
broken, curving anteriorly; antennal fovea triangular, sharply defined ; 
antenne long, slender, tapering, third and fourth joints equal or lat- 
ter longest; venation normal; intercostal vein slightly inclined; third 
cubital nearly three times as long as wide at base; stigma moderately 
robust, widest at center; sheath narrow, smooth, tapering on both 
edges to rounded tip; cerci slender, not tapering; rays of claws nearly 
equal. Color reddish yellow; antenne, spot on head surrounding 
ocelli and extending over occiput, anterior and lateral lobes of meso- 
notum, small spot beneath anterior wings, metanotum (except meta- 
scutellum, sutures, and lateral margin), abdomen (except lateral margin 
of segments and last segment), apical half of sheath, and posterior 
tibie and tarsi brownish black; antennie fulvous beneath toward tips; 
tips of anterior tarsi dusky; veins, including costa to base and stigma, 
brown, latter darker basally. 
Twelve females from Canada, Massachusetts, New York, Kansas, 
