OF WASHINGTON, VOLUME XVII, 1915 191 



I believe to represent the undescribed male of Mcniromyia pulla 

 Coq., and, after a careful study of the material in theU. S. National 

 Museum, I am convinced that Mr. Coquillett never saw the male 

 of the species. 



Since considerable dimorphism is apparent, especially in some 

 characters which have been considered as of prime specific and 

 even of generic index, it seems well to describe the male and 

 also to note some of the more remarkable variations in structure 

 peculiar to this rather extraordinary form. 



Mauromyia pulla Coq. 



Mn lr. Head (fig. I, 1.') quadrangular in side elevation, its anterior 

 border distinctly concave. Cheeks nearly as wide as eye-height. In- 

 ferior occiput swollen. Front produced directly forward, not sloping 

 downward to base of antennae. First antennal joint unusually long, fully 

 as long as second, produced upward at an angle of 45, its tip projecting 

 distinctly above the level of the front. Third antennal joint five times 

 as long as second, distinctly short pilose, its lower three-fourths strongly 

 concave on anterior border. Arista thickened on at least the basal three- 

 fourths, first joint slightly longer than broad, second joint at least three 

 times as long as broad. Facial ridges bristly on lowest third. Vibrissse 

 multiple, the larger pairs subequal, not cruciate, situated on oral margin. 

 Facial depression enormous in width, nearly twice as wide as in female; 

 genovertical plates at narrowest part not more than one-fifth its maxi- 

 mum width. Eyes small, bearing sparsely scattered hairs visible only upon 

 minute examination. Frontal bristles descending to base of arista, the 

 uppermost pair pointing distinctly outward. Front one and one-half 

 times width of eye, vitta occupying considerably more than one-half width 

 of front, brown. Sides of front cinereous, pollinose sprinkled with coarse 

 black hairs; orbital bristles absent. Face on lower half bearing two or 

 more irregular rows of small macrochscta 1 , the lowest ones reaching below 

 lower border of eye. Ocellar bristles rather weak, directed forward, the 

 postocellar pair well developed and directed vertically. Wings brownish 

 hyaline, broad, rather short, costal spine obsolete. Apical cell long- 

 petiolate, ending very slightly before wing tip. Bend of fourth vein vari- 

 able, forming an angle of 45 in some specimens (fig. 1, 2), in others bent 

 considerably inward in a distinct curve (fig. 1,3). A short stump present 

 or occasionally entirely absent. The longitudinal and cross veins bordered 

 with a light but distinct brownish stain. Hind cross-vein usually bisin- 

 uate. Sterno-pleural macrocha:t;e varying in arrangement and number 

 from two to five. Abdomen flattened ovate, slightly more slender than 

 in female'but otherwise quite similar. First segment bearing a weak 

 marginal pair, the remaining segments with both discal and marginal 

 macrochsetse. Hypopygiurn prominent, bent t'nru anl, its basal ring shining 

 black, the remainder nearly opaque. 



