1915.] NATURAL SCIENCES OF PHILADELPHIA. 511 



provided mth tinj^ hairs. Pleura very pale with a thick whitish 

 bloom. Halteres pale at the base, the knob dark bro^\ii. Legs 

 with the coxae pale, whitish pollinose; 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 brown 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, feebl}^ tuberculate, provided with many 

 long hairs. Eighth sternite very large, almost completely enveloping 

 the ninth sternite which lies in its concavity; this segment is provided 

 with abundant rather short pale hairs; at the end on either side with 

 two slender, cylindrical 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 ending 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. — Similar to the male, even in the rather peculiar 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 hicornis 

 et al.; tergal valves separated by a deep notch, the lobes with a 

 short, thick, grayish pubescence and a few longer yellow hairs; sternal 

 valves yellowish with a thick yellowish white pubescence. 



Habitat. — Northeastern United States and Canada ; Colorado. 



Holotype, cf , Orono, Penobscot Co. Me., June 6, 1913 (Alexander 

 and Parshley). 



Allotype, 9 , Dorchester, Suffolk Co., Mass., No. 482 (Uhler). 



Paratypes, No. 1, 5cf 's, topotypic; No. 6, d^, Cambridge, Middlesex 

 Co., Mass., No. 482; No. 7, 2 o^'s, Woburn, Middlesex Co., Mass. 



