1914.] • NATURAL SCIENCES OF PHILADELPHIA. 645 



800; first posterior on second posterior, 1,120; discal cell on second 

 posterior, 544; second posterior on third posterior, 320; first basal 

 on discal, 1,250; second basal on discal, 112; anal on third posterior, 

 208. 



Miocene shales of Florissant, Wilson Ranch (Wickham). It is 

 rather remarkable that the Heteromyiella type, with only short 

 bristles on the costa, should apparently (as shown by fossils from two 

 or three localities) have been prevalent in North America in Tertiary 

 times, whereas in the modern fauna it has given way to the genera 

 with long as well as short bristles. 



Empis miocenica n- sp. (Empididae). 



Length 5.5 mm., -vving a little over 5.5, middle leg about 5; head 

 about 1 mm. long, beak evident, but its length cannot be ascertained. 

 Whole insect, as preserved, light ferruginous, the abdomen with 

 dusky bands; wings reddish, ^vith a very dilute stigmatal cloud. 

 Only the upper part of the wing shows the venation clearly, but this 

 appears to be quite normal for the genus. 



The following measurements are in microns : end of first vein from 

 base of Aving, about 3,440; end of first vein to second (vertically) at 

 same level, 144; end of first vein to end of second, about 1,600; 

 separation of second and third veins from base of wing, about 1,120; 

 the two branches of third vein are about equally long (1,120), the 

 upper branch almost straight, with a very faint downward curve. 

 The auxiliary vein can be seen very close to the first, but extremely 

 weak and not reaching costa. The hind femora are large and stout, 

 ■udth a row of short, stiff, black spiniform bristles on the lower side. 

 The anterior legs are lost. 



Wilson Ranch, Miocene shales of Florissant {H. F. Wickham). 

 Considerably larger and more robust than E. florissantana, with the 

 head much smaller in proportion to the thorax. 



Empis florissantana n- sp. (Empididse). 



9 . Length about 4.50 mm. ; wings 3.25, hyahne, except for a brown 

 stigmatic cloud; middle legs about 4 mm. Face not hairy; head in 

 lateral profile broad-oval; proboscis stout and stiff, much longer 

 than head; thoracic dorsum dark; venation ordinary; hind femur 

 reaching end of fifth abdominal segment. 



The following measurements are in microns: length of head, about 

 640; leng-th of proboscis, about 1,040; anterior femur, about 1,040, 

 its tibia about the same ; end of second vein to end of anterior branch 

 of third, 272; length of anterior branch of third, 320; length of 



