186 



APPENDIX. 



Mydas audax n. sp. 



6 . — Black, second abdominal segment red 07i the dorsal as ivell as 

 on the ventral side; head, thorax and first abdominal segment with 

 whitish hairs. Length, 23 mm. Wing, 18 mm. 



Very like 3L clavatus in its coloring, but easily distinguislied by its smaller 

 size, comparatively broader head, more cylindrical sliape of the abdomen, by 

 the red color of the second segment, which does not encroach anteriorly, on 

 both sides, upon the first segment (as it does in M. clavatus), which exists on 

 the ventral as well as on the dorsal side of the segment, and which is not 

 interrupted on the dorsal side by a more or less distinct black spot ; finally, 

 by the whitish pubescence on the head, the thorax and the first abdominal 

 segment. Head black, broader than the thorax, clothed with soft, white hairs, 

 mixed with black ones ; the white hair is especially apparent on the vertex 

 and the sides of the front, also as a small tuft on each side under the antennae, 

 near the orbit of the eye, and as a border round the clypeus. Thorax black, 

 opaque ; the dorsum clothed with white hairs, forming four longitudinal bands, 

 especially visible from a side view. First segment of the abdomen black, 

 opaque, clothed with long, soft, erect white hair, which reaches down to the 

 hind coxae ; second segment shining, yellowish red, the remainder of the abdo- 

 men black, moderately shining. Venter black, except the second segment, 

 which is yellowish red. Halteres and feet black, pulvilli brownish (of a darker 

 color than in M. clavatus). Wings strongly tinged with brown, and with a 

 slight purplish reflection. Venation like that of M. clavatus. 



Belongs to Gerstaecker's first tribe, that is it has spurs at the tip of the 

 tibiae and the small cross-vein on the posterior border of the wing. 



A single male discovered in the environs of i\lummoth Cuve in 

 Kentncky, by Mr. F. G. Sanborn, in June, 1874. 



Mydas carbonifer n. sp. 



? . — Altogether black, thorax opaque, abdomen shining, wings 

 brown. Length, 22 mm. Wing, 18 mm. , 



Black, front and epistoma shining, beset with black hair; antennae black, 

 the expanded portion of the third joint brownish, and beset with a fine grayish 

 pollen. Thorax opaque above, showing two velvety black longitudinal lines. 

 Abdomen black, shining, except the first joint, which is opaque. Feet black; 

 ungues reddish, with black tips ; hind tibiae beset with strong spines, except 

 toward their base ; terminal spur strong. Halteres black ; wings' dark brown. 



