iS^o. 2313. NEW SPECIES OF EOCENE INSECTS— COCEERELL. 



249 



black in life); abdomen apparently pallid except at base; antennae 

 fuscous ; wings hyaline, somewhat dusky, with a large dark spot, and the 

 apical field suffusedly dusky. The venation is shown in the figure. 



Type.—GTQQw Kiver (Eocene) shales, Sec. 33, T. 4 S., R. 100 W., 

 Colorado (Winchester 17.6, U. S. Geol. Survey). 



Holoiype.— Cat. No. 66570, U.S.N.M. 



This ancient insect represents a type which has come down to 

 modern times generically unaltered; large size, spotted wings, and 

 all. It is much the largest of the Eocene Mycetophilidae. 



PALAEOPLATYURA (?) EOCENICA, new species. 



Plate 32, fig. 1. 



Female. — Length 5.4 mm.; head small, narrow, its width about 0.6 

 mm.; antennae with very short joints; abdomen 3.5 mm. long and 

 1.5 mxm. broad; wings 5.1 mm. long and about 1.4 broad, the very 

 obtuse apex extending about 1 mm. beyond end of abdomen. As 

 preserved, the head and abdomen are fuscous, the thorax pale fer- 

 ruginous, the wings clear hyaline. 

 The radius is thick, and about the 

 middle of the wing is 240 (j, from 

 costa. The radial sector leaves the 

 radius at a greater distance from the 

 base than is usual. 



Green River shales back of house 

 at Smith's Ranch, in the vicinity of Cathedral Bluffs, Colorado. 

 (Winchester 17.3, U.S.G.S.) 



Hohtype.— Cat. No. 66548, U.S.N.M. 



Family BIBIONIDAE. 



PLECIA WINCHESTER! Cockerell 



Several specimens from Winchester's locality 17-5 (Cathedral 

 Bluffs, south of Little Tommies Draw, "at point where samples were 

 taken") appear to belong to this species, but the exact details of the 

 venation can not be made out. They are females, v/ith the usual 

 broad abdomen. The length of the insect is from 7.5 to 8.5 mm. 

 The thorax is pallid (probably pale ferruginous in life), and the head 

 and abdomen are dark. Thus the coloration of the body agrees with 

 that of the living Plecia fuMcollis Fabricius, and the wings also 

 are about as dark as in that species. 



The new locality is about 25 miles from the type locality of P. 

 winchesteri. 



Fig. 6.— Diomonus palaeospilus. Winc 



