NORTH AMERICAN DIPTERA. Ill 



cell well opened before tip of wing; fourth vein bent at ti rii^ht 

 angle, with slight wrinkle at bend, apical cross-vein strongly bowed 

 in ; hind cross-vein not straight, well approximated to bend of fourth 

 vein. Type, S. intermedia n. sp. 



Karcofacliiiiclla iiiterineclia n. sp. '^ .— Eyes lifjlit ))r()\vii, frontal 

 vitta black ; sides of front, face and cheeks more or less silver.v, or slinlitly 

 brassy, the prte-genal area more or less shining black ; the anterior pair of ocellar 

 bristles stronji, directed forward; antennje and ari.sta brown; proboscis black, 

 labella dark brown, palpi blackish and clothed with a few black bristles; occiput 

 black, more or less shining, slightly silvery, black-bristly, with some gray hairs 

 below and a fringe of black hairs on orbital margins. Thorax cinereous, slightly 

 brassy, with three black vittie nearly reaching scutellum; sciitellum mostly 

 black. Abdomen shining black, in some lights with a slight silvery reflection ; 

 first segment with one or two lateral macrochselse, .second with a latt^ral one and 

 a median marginal pair, third with three lateral and a median marginal piair, 

 and anal with twelve or more marginal macrochsette ; hypopygium shining black. 

 hairy. Legs black, femora and tibiae bristly, femora very slightly cinereous in 

 some lights, pulvilli whitish. Wings grayish hyaline, the costo-ba.sal portions 

 irregularly yellowish along wing-veins; tegulse nearly white, halteres brownish 

 fuscous. Length of body Ss mm. ; of wing 4.5 mm. 



Described from one specimen ; Carlinville, 111. (Chas. Robertson). 



IVIegaprosopiis inichiganeiiiiiis n. sp. 9— Eyes very dark, almost 

 black, frontal vitta dark brown or blackish, front very prominent in profile, 

 about two-fifths width of head at vertex, much wider before, face nearly twice 

 as wide as front; frontal bristles descending to base of third antennal joint 

 vertical bristles strongest, and, with two next pairs, directed backward, rest for- 

 ward and inward, bristly hairs on sides of front, two orbital bristles; sides of 

 front and sides of face brassy pollinose, sides of face very wide, covered with 

 short bristly hairs; cheeks extiemely wide, distinctly wider than bight of eyes, 

 reddish brown in color, as are also the facial depression and antennre; third an- 

 tennal joint small, hardly longer than second joint; arista short, minutely pu- 

 bescent, thickened more than half its length, about same color as antennte. 

 3-jointed, first and second joints short; face very receding, facial ridges l)are 

 above constriction, approximated below facial depression for a distance fully as 

 great as length of depre.ssion, five pairs of vibrissa; bordering the approximated 

 ridges; facial depression nearly elliptical in outline, rather deep in centre; 

 cheeks bare, except bristles on edges; proboscis brown, short, fleshy, labella well 

 developed, brownisli yellow: palpi elongate, slightly thickened at tip, brownish 

 yellow, with black bristles on underside; occiput brassy pollinose, gray-hairy 

 below and sparsely black bristly above. Thorax more or less brassy pollinose. 

 with four more or less distinct dark vittfe; scutellum brassy pollinose, with an 

 apical decussate pair of macrochaitte, three lateral and two discal pairs, the pos- 

 terior lateral pair strongest, reaching not quite to base of third abdominal seg- 

 ment. Abdomen a little wider than head and thorax, large, broadly oval, black- 

 ish, second to fourth .segments mostly silvery pollinose. first segment shortened : 

 first segment with one or more lateral macrocha?t8e, second with a lateral one 

 and a median marginal pair, third with eight or ten marginal, anal with a mar- 



TR.\NS. AM. ENT. 800. XIX. MAY, 1892. 



