No. 2313. NEW SPECIES OF EOCENE INSECTS— COCKERELL. 253 



Family SYRPHIDAE. 



SYRPHUS LITHAPHIDIS, new species. 



Length, about 8.2 mm.; head and thorax 4 mm.; length of wing 

 6.8 mm. Head and thorax dark fuscous (doubtless black in life) ; 

 wings hyaline; abdomen pallid with broad dark bands on hind 

 margins of segments, and a broad dark median band, evanescent 

 on the apical half. Venation in general as in modern SyrpJius, except 

 that the subcostal ceil is not nearly so slenderly tapering at the 

 apex, the end of the first vein being somewhat like that figured by 

 Williston ^ ioT Paragus tibialis, though this does not agree well with an 

 actual specimen of P. iihialis before me. There is a distinct though 

 not dark cloud filling the apical part of the subcostal cell, as in 

 modern Syrplius. The following wing-measurements are in microns: 

 End of auxiliary vein to end of first about 1,600; submarginal cell 

 on first basal about 800; last posterior on second basal about 320; 

 tip of anal to wing margin about 240. The general form and ap- 

 pearance entirely agree with Syrplius. 



Eocene shales, '^ Cathedral Bluffs south of Little Tommies Draw 

 at point where samples were taken," Colorado (Winchester 17-5). 



Holotype.— Cat. No. 66585, U.S.N.M. 



The name is derived from that of the genus of aphides supposed to 

 occur in the Green Hiver shales. In the markings of the abdomen, 

 this closely resembles S. wiUisioni Cockerell, from Florissant. 



Family ANTHOMYIIDAE. 



ANTHOMYIA (s. !at.) WINCHESTERI, new species. 



Plate 35, fig. 6. 



Thorax about 3 mm. long, fuscous, with fine hairs and large black 

 dorsal bristles; abdomen about 3 mm. long and 2.7 wide, reddish 

 fuscous, segments 2 to 4 broadly suffused v/ith black basally, except 

 at sides; surface of abdomen with abundant small hairs; segments 

 2 to 4 with also each a transverse row of black bristles about 560^1 

 long. Legs with fine hairs and bristles, those on tibiae hardly as 

 long as diameter of tibia. The thoracic bristles are not all preserved, 

 but the achrostichal and dorsocentrals were present and very large, 

 the largest about 1,280m long; there wore apparently two large 

 humeral bristles on each side. The abdominal bristles are not pre- 

 served on the reverse impression, which shows only fine hairs in the 

 middorsal region; from this alone one might have obtained a quite 

 erroneous impression. 



Wings nearly 7 mm. long and 3 wide, duskj^, but vrithout spots ; 

 costa black, but veins very pale. 



1 N. A. DipteiS. 



