AMERICAN DIPTERA. 337 



Legs black, except the yellowish knees obsoiira Bigot. 



Legs yellow, except the darkeued tarsi IVIikii Williston. 



Hilarpmorpha obscura Bigot. 

 Bull. Soc. Ent. France (6), vii (1887), p. cxl. 

 Ann. Ent. Soc. France, 1889, p. 129. 



Entirely of an opaque hlack, except the yellowish knees; venter pruinose, and 

 of a dark gray color ; wings infumated, darker along the outer border, with an 

 elongated, diffused, blackish stigma. 5 mm. 



California. 



_ Hilaroiuorplia Mikii Williston. 



Psyche; 1888, p. 100. 



Male. — Face opaque gray, with grooves from the oral margin. Antenufe brown- 

 ish yellow; the third joint oval, a little longer than broad, the anterior borders 

 straight or gently concave to the insertion of the slender two-jointed style, which 

 is nearly as long as the body of the joint. Thorax in ground color black, thickly 

 covered with opaque yellowish pollen on the mesonotum ; on the pleurse with 

 lighter, less dense pollen. Abdomen with each segment anteriorly brownish 

 black ; posteriorly banded with opaque yellow, of a color somewhat lighter than 

 that of the mesonotum. Legs yellow, the terminal joints of the tarsi iufuscated. 

 Wings blackish, a little lighter behind. 4 mm. 



Cai'liiiville, Illinois (Robertson). 



I»IYTHI€OMYIA Coquillett. 

 Body with no raacrochfetse. Head globular, attached to a dis- 

 tinct neck. Antenuse porrect, two-thirds the height of the head, 

 the first joint very short, the second as broad as long ; the third 

 broad, lanceolate, not annulate, nearly three times the second ; style 

 terminal, nearly one half as long and one third as broad as the third 

 joint, very densely pubescent. Eyes of the male contiguous, and 

 with an area of enlarged facets above. Three widely separated, 

 equidistant ocelli present. Proboscis rigid, nearly as long as the 

 head height, directed obliquely forward, no labellse; palpi minute. 

 Thorax greatly arched, in profile higher than long. Wings with 

 the marginal cell closed, only one submarginal cell and four poste- 

 rior cells, all open, as is also the anal cell ; first section of the fourth 

 vein colorless, the last (seventh vein) very weak. Legs rather stout, 

 but none of the parts dilated, with no bristles, spines or other pro- 

 cesses ; front coxce less than one half the length of the femora; 

 pulvilli well developed, empodium bristle-like. 



Tibise, hal teres, first vein and second section of the costa yellow. 



Rileyi Coquillett. 



Tibiae, except at base, black ; upper side of knob of halteres also black ; first vein 



and costa brown tibialis Coquillett. 



TKANS. AM. KNT. SOC, XXVIII. (43) SEPTEMBER, 1902. 



