88 DIPTEEA. 



being comparatively larger. All three have a face which is not conically projecting, 

 and a comparatively long proboscis. 



11. Exoprosopa pardus, sp. n., s 2. (Tab. I. fig. 15.) 



Abdomen with, alternate cross-bands of whitish, yellow, and black tomentum ; wings pale brown between the 

 costa and the fourth vein, as far as the proximal end of the second submarginal cell, the second basal cell 

 subhyaline, the posterior cross-vein distinctly, the cross-vein at the proximal end of the second posterior 

 cell feebly, clouded with brownish. 



Length 13-15 millim. 



Hah. Mexico, Northern Sonora (Morrison). 



Antennae black; third joint elongate-conical, the style abont half the length of the 

 joint. Face conically protruding, beset with an orichalceous tomentum; proboscis 

 hardly projecting beyond the oral margin. Thorax greyish-black, the collar-like hairs 

 in front and above the root of the wings yellow; the dorsum with a sparse yellow 

 tomentum ; scutellum reddish, with yellow scales and black bristles along the edge. 

 Abdomen: the black ground-colour in well-preserved specimens almost concealed 

 under cross-bands of whitish and yellow scaly hairs, disposed as follows: — on the 

 second segment a broad whitish cross-band, the posterior margin of which is yellow ; 

 on the third segment a similar cross-band, in which, however, the yellow predominates ; 

 the fourth segment, again, is whitish, with only a trace of yellow posteriorly ; the fifth 

 and sixth yellow, the seventh white. The posterior margin of all the segments is 

 black, but this black has not always the same breadth : sometimes it forms a distinct 

 crescent on the second and third segments ; in other specimens a narrow margin only 

 (the specimen represented on the figure is of the latter class). Venter densely covered 

 with a white tomentum. Legs black. Wings pale brown between the fourth vein 

 and the costa, as far as the tip of the first vein and the proximal end of the second 

 submarginal cell ; the root is brown within the basal cross-veins ; the second basal and 

 the whole discal cells subhyaline ; proximal ends of the third and fourth posterior cells 

 with dark brown clouds ; the cross-vein at the proximal end of the second posterior cell 

 slightly clouded. Two males and five females. 



N.B. — A specimen from the same locality (a female) is larger, about 17 millim. ; the 

 proboscis projects about 1*5 millim. beyond the oral margin ; the usual tufts of black 

 hair on the sides of the segments are more conspicuous ; the scaly hairs on the sixth 

 segment are more white ; the style of the third antennal joint is a little longer. I 

 have little doubt that it is the same species. It is singular that this specimen has 

 small, but distinct, spinules on the front tibiae, while I do not see such spinules in the 

 other specimens. 



The group of Exoprosopce with an open first posterior cell, a brown antero-proximal 

 portion of the wings, and sometimes with clouded cross-veins, is numerously represented 

 in Mexico and the adjacent regions of the United States; but the species are rather 



