TA 
Three males, one from Lansing, Mich., labeled ‘‘ Lombardy poplar,” 
and two specimens bred from larve on willow by Mr. Dyar (Coll. U.S. 
Nat. Mus.). 
Mr. Dyar, for whom I determined as above some bred males, thinks 
this may prove a seasonal form of ventralis (Trans. Am. Ent. Soe., 
Xx, 1895, p. 305). Mr. Dyar’s specimens were obtained in New York 
on Salix, and, together with the types, present what seem to be good 
specific differences from ventralis. 
48. Pteronus dubius new species. 
Male.—Length 5.5 mm.; clypeus broadly emarginate, almost trun- 
cate; frontal crest very large, strongly angled anteriorly, lateral walls 
of basin tapering rapidly posteriorly; antennal fovea narrow, breaking 
slightly through crest; antennie robust, flattened, joints 4 and 5 a little 
longer than 3; venation about normal; second recurrent interstitial or 
nearly so in fore wings and the outer veins of discal cells interstitial 
in hind wings; stigma rather narrow, rounded on lower margin; pro- 
cidentia short, not very broad, apex rounded; claws deeply divided, 
rays subequal. Color black, shining; clypeus and other mouth parts 
and extending to eyes whitish; narrow line on venter of abdomen, 
including all of hypopygium and the legs, ferruginous yellow; bases 
of cox black; wings hyaline; veins and stigma brown. 
One male. Wellesley, Mass., March 29. (Coll. U. S. Nat. Mus.) 
49. Pteronus stigmatus Norton. 
1861. Nematus stigmatus (Harris) Norton. Proc. Bost. Soc. Nat. Hist., vii, p. 161. 
1867. Nematus stigmatus Norton. Trans. Am. Ent. Soc.,1, p.221. (Cat., ete., p. 83.) 
Female.—Color greenish luteous; body short and stout; antenne moderate, the 
two basal joints black; a small black spot about each of ocelli; elypeus hardly 
emarginate; labrum angulate, hairy; part of mesothorax, the metathorax, the first 
seven segments of tergum and ovipositor sheaths, and a spot on pleura below wings 
black; legs pale; tips of tarsiand claws blackish; wings hyaline; stigma and costa 
pale green. 
One female, Massachusetts. (Harris’s Coll.) 
It has the size and form of N. monochroma. 
50. Pteronus monochroma Norton. 
1861. Nematus monochroma (Harris) Norton. Proc. Bost. Soc. Nat. Hist., vim, 
Pp. L61- 
1867. Nematus monochroma Norton. Trans. Am. Ent. Soc., 1, p. 221. (Cat., ete., 
p. 83.) 
Female.—Color honey yellow; body stout; antenne wanting, except two basal 
joints, which are color of body; ocelli black, set in an irregular depression; clypeus 
retracted, crenate; Jabrum angulate; face immaculate; tegule, collar, venter, and 
cox paler than rest of body; pleura dark, almost piceus; legs color of body; 
wings hyaline; stigma and costa pale yellow. 
One female. Massachusetts. (Harris’s Coll.) 
Resembles NV. luteus, of Europe. 
