O. A. JOHANNSEN 397 



distance. Thorax black, thinly gray pruinose, the four narrow black longi- 

 tudinal stripes more or less distinctly visible; scutellum gray at the base, 

 translucent, yellow apically; one pair of inner dorso-centrals in front of the 

 transverse suture present, though but small in some specimens and absent in 

 one, dorso-centrals 2+3; "pra" about as long as the first dorso-central; 

 sterno-pleurals 1 +2; basal and subapical setae of the scutellum long, prebasals 

 and discals shorter. Abdomen ovate, as long as the thorax and scutellum com- 

 bined, black, gray pruinose, a median black stripe visible when viewed from 

 behind; third and fourth segments with a few slender discals and more nu- 

 merous slender marginals; hypopygium inconspicuous (figs. 16, 17). Legs 

 yellow; tarsi black; femoral setae sparse and slender, rows on the flexor side 

 no stronger than those on the extensor side; fore tibia without, middle tibia 

 with two posteriorly, one in the middle and one between the middle and the 

 apex; hind tibia with one (calcar) on the median extensor surface about a 

 fifth of the tibial length from the preapical; two on outer lateral extensor and 

 three on outer lateral flexor surface; claws and pulvilli moderate. Wings 

 yellowish hyaline, yellow tinged at the base, feebly rilled, veins yellow; costal 

 spine small; Ri ends opposite the r-m crossvein; R4+6 and M1+2 diverge; 

 penultimate section of M1+2 about haK as long as the ultimate section; m-cu 

 crossvein is somewhat flexed and oblique and is 1.5 times as long as the last 

 section of Cui. Squamae strongly tinged with yellow, large; the lower 

 projects half its width beyond the upper. Halteres yellow. 



Female. Front nearly a fourth wider than one eye; frontals in a single row 

 on each side sparsely placed; no cruciate setae on the front; in immature 

 specimens third antennal joint, palpi, and humeri yellowish; anterior inner 

 d. c. wanting; abdomen shorter and broader than in the male, less pruinose 

 with median line less conspicuous or entirely wanting; costal spine large and 

 the claws and pulvilli smaller than in the male. Hind tibia sometimes with 

 but two setae on the outer lateral flexor surface. Ithaca, New York, May 

 to SeptemVjer. Truro, Nova Scotia, August. 



This species has been assigned to the subgenus Euphemia, 

 even though the anterior inner dorso-centrals are rather small in 

 some individuals, absent in the females and in one of the males. 

 It bears much resemblance to P. apicalis Stein.^ 



Type (male) and paratypes in the Cornell University Collection. 

 Two paratypes (one of each sex) in the collection of the American 

 Entomological Society of Philadelphia. 



^Archiv fi'ir Naturg., vol. 79, page 46. 



TRANS. AM. ENT. SOC, XLII. 



