AMERICAN DIPTERA. 309 



. \ 



\ Empis obesa Loew. 

 Cent, i, 28. 



Male. — Cinereous, opaque. Eyes contiguous. Proboscis slender, nearly equal 

 to the body. Palpi yellow. Antennae black. Dorsum of the thorax with 

 four black vittse covered with fine whitish hairs and a little longer plack pile. 

 Margin of the scutelluiu with black bristles. Abdomen white-pilose. Hypopy- 

 gium large, swollen, ascending; lamellse obtuse at apex, the upper wholly badi- 

 ous; the central filament high and very thick. Coxae cinereous, badious at the 

 very tip, clothed with pale hairs and a few black bristles. Legs slender, simple, 

 badious, black-pilose; anterior tibiae apically and the posterior all but the base 

 dark brown ; tarsi black. Halteres luteous. Wings infuscated, veins and stigma 

 dark fuscous, the discal cell moderate, the anterior branch of the third vein very 

 oblique. 3 mm. 



Massachusetts (Scudder). 



Empis Aldrichii sp. nov. (Fig. 110). 

 Male. Length 7.5 mm. — Head and thorax black, gray poUinose, abdomen ful- 

 vous or partly black. Front and face gray pollinose ; eyes separated as widely 

 as the width of the anterior ocellus, facets small, of uniform size; face of even 

 breadth, sides of the front rounded inwardly, anterior oral margin black, shining; 

 occiput gray pollinose, black-bristly above, the bristles arranged as a postocular 

 row and scattered beyond this, with fine hairs intermixed ; on the lower occiput 

 the hairs are white; proboscis three times the length of the head, fulvous, the 

 labella black; palpi ribbon-like, pale lemon-yellow, rectangularly bent at their 

 middle; antennae as long as the face and front together, slender, the first two 

 joints yellowish, the third black, the second joint one-half the length of the first, 

 the third joint as long as the first and second united, gradually acuminate, with 

 a rather slender style one-third its length ; not conspicuously hairy. Thorax 

 gray pollinose, the pollen without any bluish tinge, but merging towards olive- 

 brown instead; tip of the humeral callosity red, shining, subhumeral spiracle 

 large, yellow ; on the middle of the pectus above each of the front coxae is a con- 

 spicuous rosette of yellowish hairs, in front of the halteres is a row of many fine 

 yellowish hairs; dorsum of the thorax opaque brown-gray pollinose, provided 

 with four chocolate-brown broad vittae, the middle pair abbreviated posteriorly 

 on the concave portion of the mesonotum, the outer pair abbreviated anteiiorly ; 

 humeri with a few short blackish bristles, sparser on the notum, intervittal spaces 

 provided with scattered short, fine yellowish hairs, the margin of the notum with 

 several black bristles, scutellum with four marginal bristles, an extra pair of 

 small ones present rarely ; the intervittal black bristles become longer in front of 

 the scutellum. Abdomen robust, as long as the head and thorax united, cylin- 

 drical, not shining (or at least but little shining on the rubbed parts), closely 

 covered with pollen, gray basally, becoming fulvous on the remainder of the ab- 

 domen, the segments rather conspicuously provided with luteous hairs ; the 

 ground color of the abdomen is piceous, with the posterior margins of the seg- 

 ments tiavescent, the last ventral segment larger, black, dusted or not, provided 

 with a few apical black spurs on the right side; hypopygium robust, more or less 

 spherical, yellowish red, its parts distinct, the filament curved, stout, partly 

 clasped near its middle by the inferior triangular lamellae. Legs moderate, sim- 



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



