May, 1920] Descriptions of Diptera 281 



middle; parafacial not as wide as third antennal segment, narrowed 

 below; arista with microscopic pubescence; third antennal segment 

 nearly twice as long as second. Presutural acrostichals very fine, in 

 four series, usually one pair longer than the others; prealar about one- 

 third as long as the bristle behind it. Abdomen depressed, sides sub- 

 parallel; hypopygium normal in size, the superior forceps with a small 

 process on each side of disc near base (Fig. 23); fifth sternite not 

 abnonnal (Fig. 12). Fore tibia usually with one anterodorsal and one 

 posterior bristle; mid tibia with one or two antero ventral, one antero- 

 dorsal, two posterodorsal, and two posterior bristles; hind tibia with a 

 series of long widely spaced anteroventral bristles which are at least as 

 long at base as at apex; hind tibia with two to four anteroventral, about 

 eight anterodorsal and four or five posterodorsal bristles, the bristles 

 of the last two surfaces unequal in lengths, the posterior surface with a 

 few setulse near base. Costal thorn short and stout. 

 Length, 6 mm. 



Type, Katmai, Alaska, July, 1917. Paratypes, one male, 

 Katmai, June, 1917; Savonoski, Naknek Lake, five males, 

 June, 1919, four males, July, 1919; one male, July 31, 1919. 



Hylemyia appendiculata sp. n. 



Male. Similar in color and markings to siibstriata Stein, and 

 sericea. Differs from substriata in having the prealar over half as long as 

 the bristle behind it, the bristles on basal half of postero ventral surface 

 of hind femur much longer and stronger, and the inferior forceps of the 

 hypopygium much longer and with a small tooth or projection on inner 

 side near apex, when seen from above (Figs. 17 and 34). 



Length, 6 mm. 



Type, Savonoski, Naknek Lake, Alaska, July, 1919. Para- 

 type, Bozeman, Mont., June 23, 1916. 



This species is very closely allied to anthracina Malloch, 

 differing in having the presutural acrostichals more widely 

 separated, the dorsocentral black abdominal vitta linear and 

 not dilated on anterior and posterior margins of each tergite, 

 the posteroventral bristles on hind femur much longer and 

 sparser, and the mid tibia with an anteroventral bristle. 



Hylemyia denticauda sp. n. 



Male. Similar to substriata in color and habitus. Differs from 

 that species in having two to three pairs of strong presutural acrostichals, 

 the prealar nearly half as long as the bristle behind it, the fifth sternite 

 glossy along inner margins of the processes and with fewer and shorter 

 hairs, the mid femur with some strong bristles on basal half of antero- 

 ventral surface, and the hvpopygium as in Figures 27 and 40. 



Length, 6 mm. 



