1915.] NATURAL SCIENCES OF PIIILADELPIirA. 511 
provided ^^nth. tiny hairs. Pleura very pale with a thick whitish 
bloom. Halteres pale at the base, the knob dark brown. Legs 
with the coxae pale, whitish poUinosc; trochanters dull yellow; 
femora and tibiae brownish yellow; tarsi brownish. Wings whitish, 
subhyaline, the costal cell yellowish, the stigma rather indistinct, 
dull yellow. Venation as in Plate XVII, fig. 23. 
Abdominal tergites dull yellow to brown, densely provided with 
short hairs; eighth segment black; ninth segment reddish broA\Ti at 
the base on either side, dark brownish black on the caudal half; 
sternites dull yellow, the massive eighth sternite orange-brown. 
Hypopygium of the male (see Plate XVIII, fig. 43) with the eighth 
tergite small, rather narrow. Ninth tergite (see Plate XIX, fig. 60) 
rather small, quadrate, the outer lateral angles produced caudad 
into prominent sharp points; the caudal margin of the segment 
with three lobes, of which the median one is smallest. Ninth pleurite 
complete but rather narrow, the appendages complex, the inner 
lobe ending in a compressed flattened arm which is produced into a 
cephalad-directed point; behind this last lobe is a second one, 
shorter, more cylindrical, feebly tuberculate, provided with many 
long hairs. Eighth sternite very large, almost completely enveloping 
the ninth sternite which Hes in its concavity; this segment is provided 
with abundant rather short pale hairs; at the end on either side mth 
two slender, cyhndrical chitinized points; the space between them 
on the caudal margin with a dense brush of short hairs. Ninth 
sternite with a chitinized appendage at the tip, this being shaped as 
in Plate XX, fig. 74; it is slender, expanded at the tip and enchng in a 
long, slightly curved point which is surrounded by a few blunt teeth; 
the inner face is provided with numerous long hairs directed mesad. 
Female.— ShmlsiV to the male, even in the rather pecuhar venation; 
antennae short, the extreme base of each flagellar segment dark, the 
remainder with a whitish bloom. Ovipositor with the valves very 
shortened (see Plate XXI, fig. 87) somewhat fleshy, as in bicornis 
et al.; tergal valves separated by a deep notch, the lobes ^^dth a 
short, thick, grayish pubescence and a few longer yellow hairs; sternal 
valves yello^vish with a thick yellowish white pubescence. 
Habitat. — Northeastern United States and Canada ; Colorado. 
Plolotype, &, Orono, Penobscot Co. Me., June 6, 1913 (Alexander 
and Parshley). 
Allotype, 9 , Dorchester, Suffolk Co., Mass., No. 482 (Uhler). 
Paratypes, No. 1, 5c^'s, topotypic; No. 6, d" , Cambridge, Middlesex 
Co., Mass., No. 482; No. 7, 2 d"s, Woburn, Middlesex Co., Mass. 
