Sept. 1898] COQUILLETT I On DIPTEROUS FAMILY SCATOPHAGID.E. 163 



base of palpi yellow, remainder white, halteres, femora, tibia and tarsi yellowish, 

 wings hyaline ; face silvery white, body brownish gray pruinose. Length, 5 mm. 



White Mts., N. H. Two males collected by the late H. K. Mor- 

 rison. Type No. 4097. 



Chaetosa, gen. nov. 



The type species is Cordylura punctipes Meig., of which the Na- 

 tional Museum possesses two specimens from Minnesota, one from Colo- 

 rado and two from Holland. This species could never be identified by 

 the use of Becker's monograph, since he places it in the genus Tricho- 

 palpus, to which, both in the table of genera and in the definition of the 

 genus, he attributes a single sternopleural macrochreta. The palpi are 

 sub-lanceolate, slightly flattened, and at the apex of each is a black 

 bristle which is much longer than any of the adjacent ones. 

 Acicephala, gen. nov. 



Closely related to Cordylura but readily distinguishable by the 

 elongated, flattened head and very oblique face. Type, the following 

 species : 

 Acicephala polita, sp. nov. 



Black, the face, cheeks, palpi, halteres, coxae, femora, tibiae and tarsi, yellowish ; 

 front, except the ocellar triangle, inner side and apex of second antennal joint, face, 

 cheeks and pleura white pruinose, the occiput, mesonotum, scutellum and abdomen, 

 polished ; second joint of antennae prolonged over the inner side of the first nearly to 

 the arista, the third joint two and one-half times as long as broad, only slightly longer 

 than the second, arista rather long plumose, thickened on the basal fifth, the penulti- 

 mate joint broader than long; eyes bare, nearly perpendicular, only slightly higher 

 than long; vibrissas more than twice as long as the adjoining bristles, lateral oral 

 margin bearing three or four black bristles on its anterior half; palpi clavate, slightly 

 flattened, bearing several long yellowish bristles near the middle, a few short black 

 ones at the tip besides one which is nearly as long as the palpi ; proboscis robust, only 

 slightly over twice as long as thick. Mesonotum almost destitute of bristly hairs, five 

 stout dorso-central macrochaatae, one prothoracic, one sternopleural, and two on the 

 scutellum ; abdomen less polished than the mesonotum, destitute of stout macrochaetas, 

 its hairs black, those on the venter except at the apex, whitish. Win^s hyaline, 

 tinged with brown along the veins, third and fourth veins toward their apices parallel, 

 the fourth ending far beyond the apex of the second, small crossvein beyond the mid- 

 dle of the discal cell, and far beyond the tip of the first vein, all veins bare. All 

 femora and tibiae bearing macrochartae, hind tibiae each bearing three pairs on the 

 outer side beside those at the tip. Length, 7 to 8 mm. 



Colorado. One male and three females. Type No. 4098. 



Acicephala pilosella, sp. nov. 



Same as the above description of polita with these exceptions : Face, cheeks, 

 palpi, coxae and femora black ; pruinosity of front, face, cheeks, and pleura, brownish 



