AMERICAN DIPTERA. 315 



Female. — The female differs from the male in the following characters: eyes 

 separated nearly twice as widely as the posterior ocelli ; scutellum generally with 

 eight bristles; abdomen more flattened, tip not deflected, color of the abdomen 

 more yellowish gray ; the hairs of the legs much reduced, those of the underside 

 of the femora more evidently bristle-like ; tibiae not as thick as the femora ; only 

 one long costal bristle near the base of the wing. 5.5 mm. 



Alabama (C. F. Baker). 



Empis teres sp. nov. (Figs. 133-142). 

 Male and Female. Length 4-5 mm. — Black; silvery gray poUinose (female less 

 silvery). Occiput, front and face gray pollinose ; eyes maroon color, facets uni- 

 formly small, eyes of the male separated the width of the front ocellus, the front 

 of the female broader ; palpi short, slender, not exceeding the mouth-opening, 

 pale yellow ; proboscis once and one-half the eye-height, slender yellowish ; an- 

 tennse slender, as long as the eye-height, first joint moderately long, first and 

 second fuscous, third joint black, as long as the first two together, arista one-third 

 the length of the third joint; bristles of the occiput arranged in two definite 

 rows. Thorax dusted with silvery gray in the male, female with a slightly 

 brownish tinge to the notum, dorsum with indications of four darker vittse, the 

 outer two abbreviated in front, and very faint, the iutervittal spaces with sparse 

 short black bristles, but few humeral and marginal bristles, the series in front of 

 the h:ilteres indefinitely consisting of about five bristles, of which only two are 

 long ; scutellum with from four to six marginal bristles, generally with two well- 

 separated median and two short outer bristles; pectus devoid of bristles. Abdo- 

 men sparsely hairy, dull grayish in the female, silky white pollinose in the male, 

 ground color of the narrow posterior margins of the individual segments whit- 

 ish ; hypopygium compressed, narrow, gaping, the central filament slender, 

 strongly bowed, hidden at the very tip, the lamellae extending obliquely upward, 

 lightly dusted, middle lamellae emarginate above, the upper laniellte not deeply 

 but broadly excised above. Coxae and legs yellowish, the tips of the trochanters 

 and of the femora narrowly black, the black hairs of the legs not dense, in the 

 male the hairs are long, especially on the outer portions, tarsi and more or less 

 of the tip of the tibiae darkened ; legs of the female simple and slender, of the 

 male slender, but the tip of the hind femora beneath with three subterminal 

 small tubercles in longitudinal series, the proximal globose, the middle one a 

 little toward the inner side, truncate and bounded outwardly by a distinct black 

 spine, the third medially placed and bounded both inwardly and outwardly by a 

 row of black bristles, the outside row being of greater extent; corresponding 

 with the femoral tubercles the base of the tibia is peculiarly dentate, the three 

 basal teeth evident and each tipped with a black spine, beyond the teeth the 

 under edge of the tibia is serrulate and ciliate with short black hairs; the hairs 

 of the outer edge of the tibiae and tarsi long, tarsi of both male and female be- 

 neath with short tliick black bristles, metatarsi about equal to the next three 

 tarsal joints, the front metatarsi of the female and the middle metatarsi of the 

 male are, however, shorter, the hind metatarsi of the female and the fore and 

 iiind ones of the male are as thick as the tips of the tibiae. Halteres pale yellow. 

 Wings clear hyaline, veins narrow fuscous, stigma obsolete, the third vein 

 stronger than the others, furcate before the tip of the marginal cell, the furcation 



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



