1925] 
The Eocene Fossil Fly Eophlebomyia 
229 
THE EOCENE FOSSIL FLY EOPHLEBOMYIA. 
By T. D. A. Cockarell. 
University of Colorado, Boulder, Colo. 
In 1922 a remarkable fossil fty, evidently representing an 
undescribed genus, was found in the Green River Eocene shales 
near De Beque, Colorado. I described it in Proc. U. S. National 
Museum, Yol. 64, Art. 13, p. 4 (1924) as Eophlebomyia clari- 
pennis, with an enlarged figure from a photograph by Dr. R. S. 
Bassler. With hesitation, I placed it in the Trypetidae, remark- 
ing: “I at first thought to refer it to the Anthomyiidae, but it 
appears to be acalyptrate, and the venation agrees better with 
Trypetidse. In certain respects, it agrees with what we should 
expect to find in an ancestor of the modern Trypetidse.” Some 
time after, I found I had a second specimen from the same region, 
and this I sent to the British Museum. I was particularly 
anxious for Major E. E. Austen to examine it, because the fly, 
as I had stated in my description, resembled Glossina in the 
course of the fourth longitudinal vein. In his Handbook of the 
Tsetse-flies, Austen called attention to this character in Glossina 
as something absolutely unique. 
Major Austen very kindly examined the fossil at once, and 
wrote at length concerning it. I urged him to publish an article, 
but he asked me to do whatever seemed necessary, giving full 
permission to quote his opinions. I meant to wait until again 
publishing on Eocene insects, but as such publication may not 
occur for a long while, it seems best to offer the present dis- 
cussion. Major Austen wrote (Dec. 13, 1924): 
“ After making as careful an examination of the specimen as 
I can, I am inclined to doubt whether the species belongs to the 
Acalyptratae at all. I certainly can’t distinguish any squamae, but 
that doesn’t prove the absence of these structures. In spite of 
the Trypetid-like character of the auxiliary vein, the extreme 
shortness of the anterior transverse vein, coupled with the ap- 
parent absence of bristles on the extensor surface of the tibiae, 
in my opinion renders the inclusion of the species in the family 
Trypetidae impossible. The short anterior transverse vein is 
