NEW TERTIARY INSECTS. 



By T. D. A. COCKERELL, 



Of the University of Colorado , Boulder. 



The insects now described come from three different locahties and 

 horizons. One species was obtained by the United States Geological 

 Survey in the oil shales (Eocene) of western Colorado. Others are 

 from Florissant, Colorado, where they were obtained in the well- 

 known Miocene shales. These include, in addition to a number of 

 new species, new genera of Diptera and Hymenoptera. AU the above 

 are in the United States National Museum, but I have also included 

 some descriptions of species from the Ohgocene of Gurnet Bay, Isle of 

 Wight, England, transmitted for examination by the British Museum, 

 through the kindness of Dr. F. A. Bather. These came originally 

 from the collection of the Rev. P. B. Brodie, as did those in the United 

 States National Museum which I recently described in these pro- 

 ceedings.^ 



DIPTERA. 



RIPHIDIA BRODIEI. new species (Tipulidae). 



Plate 31, fig. 2. 



Wing about 5 mm. long and 1.5 wide, pale brownish, with very faint 

 clouds at ends of first marginal and first basal cells; costa with minute 

 bristles, but no evident bristles on the veins; venation almost exactly 

 as in R. maculata Meigen. The following wing measurements are in 

 microns : first basal cell on first marginal (not allowing for curve) 770 ; 

 first basal on submarginal (not allowing for curve) 432; first basal on 

 first posterior, 130; first basal on discal, 336; upper side of discal cell, 

 640; discal on second posterior, 130; discal on third posterior, 320. 



Ohgocene: Gurnet Bay (Brodie). British Museum, I. 8603. 



MONGOMA CRUCIFEKELLA, new species (TipnUdae). 



Plate 31, fig. 3. 



Wing about 5 mm. long, hyaUne, without spots, veins brown; vena- 

 tion agreeing in general character with hving Mongoma, the anterior 

 cross-vein apparently absent (fused with R4+5) ; veins at apex of first 



» Proc. U. S. Nat. Mus., vol. 51, 1916, pp. 89-106. 



Proceedings U. S. National Museum. Vol. 62-No. 2181. 



373 



