22 H. C. HrcKETT 



Hylemyia arnolitra sp. nov. 



Male. — Blackish species. Head blacMsh; parafrontals and parafaeials of dense grajish 



velvet ■pritli whitish pniinescence; cheeks reddish brown, with whitish pruinescence. -Intennae 

 blackish, first and second segments covered with dense grajish velvet; third aristal segment 

 slightly reddish brown beyond basal swelling. Palpi black. Thcrax blackish, with shght 

 cinereous poUen; viewed from above and behind, the mesonotum with traces of a median 

 vitta, the sides of the disk between the alar callosities and the transverse suture with a 

 noticeable black patch; also, a noticeable dark fascia on each side behind posthumeral bristles, 

 humeral callosities with lighter. gra\-ish poUen. Abdomen, viewed from above and behind, 

 with dense grayish pollen and a distinct, linear, black, dorsocentral ^itta; anterior margin 

 of each tergiun with blackish uniform incista'e; h\-popygium not so densely polhnose, 

 subshining. Legs black. Wiup clear; veins brownish; r-m and rn-c^j, cross-veins faintly 

 clouded. Calj-ptrae white. Halteres yellow. 



Eyes separated, at narrowest part, by a distance equal to that between posterior ocelli. 

 Parafrontals and parafaeials, in profile, prominent, at base of antennae equal in width to 

 breadth of third antennal segment, parafaeials rapidly receding ventrad to narrower propor- 

 tions. Antennae short, the third antennal segment nearly as broad as long; arista minutely 

 pubescent, noticeably swollen at base. Acrosticals distinct, irregularly placed in two closely 

 adjacent rows. Pra short. Stemopleurals, 2:2. Abdomen cylindrical, longer than thorax; 

 terga with strong lateral bristles on disk, besides the usual marginal bristles. .Second sternum 

 with a noticeably stronger growth of bristles and setae than remaining sterna. H\-popygium 

 small and inconspicuous, largely inclosed within fifth tergum; processes of fifth sternum small 

 and short, apices and outer border bare, inner area clothed throughout with setulae. inner 

 margins interrupted by a median prominence. Fore tibia with one median and one weak 

 apical postero ventral bristle. !Mid femur with two or three short, stout, median ant ero ventral 

 bristles, and a proximal row of similar posterodorsal bristles; mid tibia with one anterodorsal, 

 two posterodorsal, and two or three posteroventral bristles, the last-named bristles and the 

 upper posterodorsal bristle reduced and appearing as setulae. Hind femtir with & row of short, 

 stout, anteroventral bristles, the longest not exceeding the breadth of the femur where they are 

 situated: also, an interrupted series of short posteroventral bristles; hind tibia ^ith three 

 weak anteroventral, five diverse anterodorsal, and three posterodorsal bristles; two or three 

 setulae on posteroventral surface; strong postero- and anteroventral apical bristles. Tarsi 

 laterally compressed; pul%iUi and claws noticeably long. Costal thorn small. Cah-ptrae 

 subequal. Length, 5.5-7.5 mm. 



Female. — .Similar to male except for the following characters: Abdomen with a broad, 

 brownish, dorsocentral vitta, tapeiing caudad, and incLsuxes that are not well defined. 

 Frontal ^-itta blackish, with cruciates minutely developed. Length of pra exceeding half 

 that of the foUowtng bristle. Bristles and setae of second abdominal sternum .similar to 

 those of remaining sterna. Legs with bristles more strongly developed than in male. Fore 

 tibia with one dorsal, one posterior, and two posteroventral bristles, the apical postero- 

 ventral bristle weU developed. Hind femur with three or four bristles di.5peT.sed along antero- 

 and posteroventral surfaces; hind tibia with no settilae on posterior surface. Tarsal claws 

 andpulviUi of moderate size, shorter than in male. Costal thorn distinct; cross-veins dis- 

 tinctly clouded. Length, 6 mm. 



Localities. — 1 1 . Hempstead, Long Island, April 10, 1921; .3 6 • April 12, 1921; 1 2 , Ithaca, 

 May 8, 1915. 5 specimens: 4 males, 1 female. Figures 16, 60, 113, on plates in this memoir, 

 i^ Type. — In the Cornell L'niversity collection, Ithaca, New York. 



Allotype. — In author's collection. 



Paratype. — In the United .States National ilusetun collection, Washington, D. C. 



In the male specimens before the writer, the distance between the ej'-es 

 varies, but in no case is it less than the di.stance between the posterior 

 oceUi. Similarly, the length of the prealar bristle varies, but in no case 

 does the length exceed two-thhds that of the following bristle. 



