278 A. L. MELANDER. 



LAilIPRElflPliii gen. nov. 

 Lamprempis Wheeler et Melander (Subgen. Empis), Biol. Cent. Am., 1901, Dipt. 

 Suppl., p. 366. 



Small, short, broad, greatly humpbacked, metallic blue or blue 

 green flies. Eyes of the male contiguous. Thorax often with 

 bushy short pubescence, the macrochsetse much reduced, either 

 wanting or hair-like, even on the scutellar margin. Hypopygium 

 prominent, three lateral valves varyingly developed, the central 

 filament much reduced, generally apparently wanting. Legs of 

 both sexes ornamented, of the female ciliate with scales or hairs on 

 the edges, of the male sometimes more or less pennate. Chichimeca 

 possesses remarkable processes on the male hind leg which are de- 

 veloped not alone at the knee, where similar processes are developed 

 in typical Empis, when they occur, but also on the distal portion of 

 the tibia and on the metatarsus; in benigna and snperbn also, there 

 are thickenings in the same places ; violacea, the only other species of 

 which the male is known has no similar thickenings of the legs, but 

 has instead the pennate ornamentation. Wings with the character 

 istic brownish tinge of the Mexican flies, more or less developed, 

 most conspicuous along the costa ; the veins narrow, brownish, be 

 coming faint posteriorly, especially the anal and sometimes the fifth 

 also; the third vein furcate far beyond the end of the marginal cell, 

 its anterior branch perpendicular. 



Wing« hyaline, marked with black ; hind legs of n^ales with scales. 



Tiolacea Loew. 



Wings uniformly blackish ; legs of male simple superba Loew. 



Wings hyaline or yellowish 2. 



2. Tarsi black ; middle and hind femora and tibiie with flat scales on both edges 



(female) cyanea Bellardi. 



Tarsi at most fn^cous 3. 



3. Wings clear hyaline; legs not ciliate with scales (female) • • • Siiavis Loew. 

 Wings of a yellowish tinge 4. 



4. Scales dense on both sides of the middle and hind femora and tibise (female) ; 



hind femora, tibise and metatarsi each with a peculiar process (male) ; 



wings uniformly colored cliicltimeca Wheeler et Melander. 



Scales few on the upper side of the femora (female) ; wings darker on the an- 

 teroproximal portion 5. 



5. Hind tibisB and metatarsi each with a brush of hairs (male) ; third anteunal 



joint shorter than the first two united benigna Osten Sacken. 



Third antennal joint about equalling the first two. 



diaphoriiia Osten Sacken. 



Lamprempis violacea Loew (Figs. 103, 104). 

 Cent, viii, 55. 



Male. — Blue, shining, covered with fine black pile. Head blue-black ; eyes 



