THE GENUS TACHINOMYIA — WEBBER 301 



TACHINOMYIA NIGRICANS, new species 

 FiGUBE 17, b 



Resembles acosta but differs from that species in the structure of 

 the anal forceps and their lack of dense pilosity. 



Male. — Hind tibiae inwardly with short villosity, the villi scarcely 

 the tibial width in length ; lobes of fifth sternite black, without basal 

 flange, their inner edges smooth or at most with low, inconspicuous 

 ridges; fourth sternite convexly produced; fourth abdominal seg- 

 ment not densely gray pollinose but mostly black, mottled with thin 

 grayish pollen, apical border shining black; scutellum black, thinly 

 gray pollinose; second genital segment black above, reddish beneath; 

 second antennal segment black with brownish apex; third segment 

 hardly twice its length; anal forceps (fig. IT, h) moderately pilose 

 behind, nearly straight, tapering abruptly to terminus; four dorso- 

 central bristles; no posterior preintraalar bristle; front and face 

 silvery gray pollinose, with yellowish cast; parafacialia at narrow- 

 est part compared with distance between vibrissae 7.1:18.6 (av- 

 erage of six) ; cheeks about one-fourth of eye height, with pale hairs; 

 facial ridges bristly about halfway to antennae; vibrissae slightly 

 above oral margin. Length, 11-16 mm. 



Female. — Doubtfully known. 



Type.—M^\Q, U.S.N.M. No. 53389. 



Rernarhs. — The holotype is from Lunenburg, Mass., coUex^ted by 

 H. W. Allen during 1916. The two paratypes are from Wellesley, 

 Mass. (J. D. Tothill, June 1, 1909), and Morris County, N. J. (R. T. 

 Webber, May 10, 1936). Other material, in the INIelrose Highlands 

 laboratory collection, consists of 60 males from localities in Massa- 

 chusetts, some of which are bred specimens. All agree well with 

 i\\Q, type, particularly as regards the structure of the anal forceps; 

 the lobes of the fifth sternite are black, practically smooth, or each 

 bears an inconspicuous ridge; the anal forceps are moderately pilose 

 behind, rarely more so. There is some variation in the number of 

 dorsocentrals, 8 out of 60 males having 3 instead of the normal 4. 

 Of all the specimens examined none had a posterior preintraalar 

 bristle; the genital segments are black above, usually reddish be- 

 neath; the scutellmn and second antennal segment are mostly black. 

 Usually there are 11 or 12 frontal bristles, rarely less; the face and 

 front are silvery gray pollinose with yellowish cast in all but two 

 specimens, in which they are silvery. 



Another lot of males from Massachusetts localities number slightly 

 over 100 specimens. All have the vibrissae on or slightly above the 

 oral margin ; the first and second genital segments are entirely black, 

 or black above and reddish beneath; normally there are four dorso- 



