100 PROCEEDINGS OF THE NATIONAL MUSEUM vol.98 



type specimen thompsom (female) is a poor one. It has two reclinate 

 upper frontal bristles besides the prevertical one ; the second segment 

 of the antenna is rufescent; the midtibial bristles are not typical of 

 either form but nearer &udryae\ it has three of these, with one between 

 the lower and middle bristles; apparently it has an interrupted dorsal 

 vitta on the abdomen. As eudryae females quite often have two re- 

 clinate upper frontals besides the prevertical bristle (maximum dis- 

 crepancy from alypiae females) and the second joint of the antenna 

 is rufescent, the above synonymy is confirmed. 



Head with front of male at the narrowest 0.24, 0.25, and 0.26 (in 

 three specimens) and front of female about 0.30 of the head width, 

 frontalia about one-third width of front, brown; frontal bristles exclu- 

 sive of reclinate frontals seven to nine in number (often six in the 

 female), extending down to base of third antenna! joint; female with 

 two proclinate fronto-orbital bristles; facial ridge bristly on lowest 

 third, gena about one-seventh eye height ; arista brownish black, thick- 

 ened basally, penultimate joint short; palpus yellow, somewhat thick- 

 ened and curved at tip. 



Thorax black with a bluish tinge and lightly covered with grayish 

 pollen; five narrow black mesonotal vittae; four postsutural dorso- 

 central macrochaetae; scutellum bluish gray pollinose, yellow at tip, 

 four pairs of marginal scutellars (one of the marginal pairs usually 

 weaker) and one decussate apical pair, one pair of discal scutellars: 

 three sternopleural macrochaetae ; front tibia with two bristles on me- 

 dian posterolateral side ; hind tibia ciliate comblike, usually with one 

 longer bristle; wing grayish hyaline, third vein with two bristles at 

 base; squamae silvery white. 



Abdomen shining black, second to fourth segments light-gray pol- 

 linose with more or less of a bluish tinge except posterior borders and 

 a median dorsal vitta, which are shining black; males usually with 

 second and third segments faintly reddish on sides; first and second 

 segments each with one pair of marginal macrochaetae, the third a 

 marginal row, and the fourth irregularly tipped with marginal and 

 submarginal bristles; third abdominal segment of male with a dense 

 patch of hairs underneath on each side. 



Length 6 to 8 mm. 



Type locality. — Ithaca, N. Y. 



Distribution. — New Hampshire 1, Vermont 1, Massachusetts 4, New 

 York 2, Pennsylvania 1, New Jersey 1, Maryland 1, Virginia 1, North 

 Carolina 1, Ohio 1, Ontario. Additional published and unpublished 

 records not duplicated above: Maine (Johnson), Connecticut (Ely, 

 Aldrich and Webber), New York (West), Kansas (Snow), Quebec 

 (Winn and Beaulieu), Ontario (Gibson). Coquillett records New 



