March 1897.] 
Dyar: Larwe of Saw-Flies. 
25 
nounced. A green elevation of the upper surface; below a thin skin, 
not swollen, but slightly yellowish ; the leaf rolls over tightly in a close 
coil to two whole turns, finally as far as the midrib, from one half to the 
whole of one side of the leaf being involved. The little larva lives in 
the gall, but soon comes out of it and rests in the rolled part. 
Stage II. —Head pale brownish, the eye black; width .3 mm. 
Body all whitish, food forming a narrow green line; slightly shining, 
annulated, thoracic feet of good size. 
Stage III. —Head and anal flap shining black ; width .4 mm. 
Body whitish, slightly shining, annulate. 
Stage IV. —Head shining black; width .55 mm. Body shining, 
no distinct setae, irregularly 4-to 5*annulate; feet on joints 6 to 11 
and 13. Body whitish, slightly opaque, food green; the whole of anal 
flap black; anal prongs short, black. 
Stage V. —Head pale in the sutures, a large black patch on each 
lobe and one in the clypeus; width .8 mm. Body 3-annulate, smooth, 
not shining, whitish with a slight yellow-green tint, food green; anal 
end concolorous, no patch at all, though the frass gives a dusky shade. 
Prongs very short, brown tipped. The larvae eat the parenchyma only, 
as in the preceding species. 
Found on willow at Van Cortlandt Park, New York City. 
Pteronus dyari Marlatt. 
I supposed this species to have been bred from the same larvae 
which produced Amauronematus luteotergum (Trans. Am. Ent. Soc., 
xxii, 304), but Mr. Marlatt finds the flies distinct. Further observa¬ 
tions are needed. 
Pteronus hyalin us Marlatt. 
I have described the larvae as Nematus lateralis (Trans. Am. Ent. 
Soc., xxii, 307). 
Pteronus lombardae Marlatt. 
Larvae indistinguishable from those of P. ventralis , feeding on pop¬ 
lar instead of willow (Trans. Am. Ent. Soc., xxii, 305 ). 
Pteronus populi Marlatt. 
Indistinguishable from P. hudsonii Dyar in coloration in the last 
stage. 
Egg .—In a cluster of saw cuts close together, but irregular, under 
the lower epidermis at the apex of a leaf. 
Stage I .—Head .6 mm. Larvae all blackish. Gregarious, eating 
holes in the leaf. 
