SCUDDEE ON FOSSIL INSECTS. 755 



respect, the genus differs also from other 3Iyopidw, as it does also in the 

 extreme length of the third basal cell, which is as long as in Syrpliidm. 

 In these points of neuration, it would seem to agree better with the 

 PipuncuUdcB, which family, however, is entirely composed of very small 

 flies, so that it seems better with our imperfect knowledge of the fossil 

 to refer it to the llyopidce. The body resembles that of Syrphus in gen- 

 eral form. The wings are as long as the body, and slender, with very 

 straight veins 5 the auxiliary and first to fourth longitudinal veins are 

 almost perfectly straight, the third originating from the second longitudi- 

 nal vein at some distance before the middle of the wing 5 the auxiliary vein 

 terminates beyond the middle of the costal margin ; directly beneath its 

 extremity is the small transverse vein, and about midway between the 

 latter and the margin the large transverse vein uniting the fourth and 

 fifth veins ; the extremity of the second basal cell is further from the 

 base than the origin of the third longitudinal vein, and the third basal 

 cell reaches very acutely almost to the margin of the wing, 



FoUomyia recta. — The single specimen (No. 14696) referable to this 

 species was obtained by Dr. Hayden at the " Petrified Fish Cut", and 

 represents a dorsal view of the insect with the wings partly overlapping 

 on the back. It is the smaller fly referred to in Dr. Hayden's Sun Pic- 

 tures of Eocky Mountain Scenery, p. 98. The head is broken ; the tho- 

 rax is stout, rounded-ovate, and blackish ; the scutellum large, semi- 

 lunar, and nearly twice as broad as long, with long black bristles along 

 either lateral edge and along the sides of the thorax posteriorly. The 

 wings are long and narrow ; the auxiliary vein runs into the margin 

 just beyond the middle of the wing ; the first longitudinal vein runs into 

 the margin at about two-thirds the distance from the tip of the auxiliary 

 vein to that of the second longitudinal vein, and scarcely turns upward 

 even at the tip ; the straight second and third longitudinal veins diverge 

 from each other at the extreme tip after running almost parallel through- 

 out the length of the latter, which originates from the second some dis- 

 tance before the middle of the wing ; the small tranverse vein between 

 the third and fourth longitudinal veins lies just beyond the middle of 

 the wing and perpendicular to the costal border, while the large trans- 

 verse vein between the fourth and fifth longitudinal veins is perpen- 

 dicular to the latter, and renders the discal and second posterior cells 

 of about equal length. The abdomen is apparently lighter- colored than 

 the thorax, regularly obovate, as broad as the thorax, and longer than 

 it, its terminal (fifth) segment sm'all, the others large and subequal. 



Length of thorax and scutellum 4'"'" ; breadth of same 2.75""^ ; length 

 of abdomen 4.5'"°^; breadth of same 2.75™™; length of wing 6.5™™; 

 breadth of same 2.25™™. 



I am indebted to Mr. Edward Burgess for some critical remarks upon 

 the affinities of this fly, and for a careful sketch of the neuration, which 

 is very difficult to trace in certain places. 



