AMERICAN J)IPTERA. 327 



the base, provided with one loug and several short preapical fine black hairs ; 

 labella more deeply bifid than usual in this group ; first antennal joint two times 

 the second; the third joint rather slender; postocular bristles short. Protho- 

 racic collar even; humeral bristles small; no pectal bristles; scutellar bristles 

 inconstant, generally two small and two minute bristles; the row in front of the 

 halteres with three to five small bristles. Abdomen slender, long ; the middle 

 lamellfB of the hypopygium erect, strongly shining, covering the upper lamellse, 

 the swollen basal part of the central filament visible. Coxae reddish apically, or 

 wholly yellow, their bristles reduced ; legs slender, hind femora shorter than the 

 abdomen ; legs reddish, except the front tarsi and more or less of the remaining 

 tarsi, which vary from brown to black ; front metatarsi of the male three-fourths 

 as long as their tibiae and of slightly greater diameter ; bristles of the legs be- 

 coming fine and long apically, especially on tlie outer side of the male hind tibiae ; 

 the spine-like bristles of the plantar surface of the tarsi rather long; armament 

 of the hind knees of the male close to the feraero-tibial joint ; hind femora slen- 

 der, but little thickened at the armament, hind femora and tibiae but little bent; 

 nenr the tip of the hind femur the underside is produced into a short, bipartite, 

 transverse process, the inner projection of which is short and sharply angular, 

 the outer flattened, situated on the median line and capped by a close fringe of 

 short black scales; between this structure and the tip of the femur is a short 

 sharp, backwardly directed, median tooth ; hind tibiae gradually enlarged from 

 the knee, the slender base with a single long process on the under side, tipped 

 with a pencil of black bristle-like hairs; these structures are not bounded by 

 fringes of bristles. Wings long, slender, very lightly infumated ; the third vein 

 furcate before the tip of the marginal cell, the posterior branch curved backward 

 ending beyond the tip of the wing; posterior cells long; hind margin of the dis- 

 cal cell nearly one-half the length of the outward continuation of the vein, the 

 first section of the anterior border nearly one-fourth the length of the second 

 section. 



Seven males, one female ; Idaho, Oregon. 



Empis iiiixopolia sp. nov. 

 Male and Female. — Rather stout small species of gray-brown color. Palpi infus- 

 cated more or less at the base, and with one distinct preapical bristle beneath ; 

 first antennal joint once and a half the length of the second joint, the third joint 

 comparatively small ; occipital bristles moderately long, in two well-defined rows. 

 Thorax gray, more or less olivaceous on the dorsum and with the vittae brown, 

 scutellum gray, provided with four marginal bristles; the bristles of the pronotal 

 collar long; a small bunch of hairs present on each side of the pectus; about 

 ten uneven bristles in front of the halteres; between the four macrochaetae above 

 the base of the wing and the humeral macrochaetae at most but three minute 

 bristles on the margin of the mesonotum, the humeri with few minute bris- 

 tles ; abdomen with small bristles towards the base ; middle lamellae of the hypo- 

 pygium yellowish at the extreme tip, not entirely concealing the upper lamellse ; 

 the whole of the thickened base of the central filament exposed ; hairs of the 

 li.vpopygiiini short. Coxae darkened at the base, their hairs minute ; legs robust, 

 short, reddish, the tarsi and the upper side of the femora blackened ; the bris- 

 tles of the outer side of the tibiae strong, uniformly widely distant (i.e., six on 



TRANS. AM. ENT. SOC, XXVIII. SEPTEMBER, 1902. 



