56 T. D. A. Cocker ell — Descriptions of Tertiary Insects. 



Hab. — Florissant in the Miocene shales, 1908. On the same 

 slab, close to the fly, are the leaves of Fagus longifolia. While 

 I was preparing the above description, Dr. A. C. Peale, the 

 discoverer of the Florissant shales, visited my laboratory. It 

 is with much pleasure that I dedicate the species to him. 



Holotype in Peabody Museum (Yale). 



Pachysystropus gen. nov. (Bombyliidae). 



Rather large, cylindrical-bodied, with a strong projecting 

 proboscis ; antennae witli a sharp apex, constructed essentially 

 as in Geron • hind femora stout and hairy. In Williston's 

 table (N. Am. Diptera, 3d ed.) it runs straight to Dolichomyia 

 (the eyes are not very distinct, but I feel sure not holoptic), 



Fig. 1. 





Pachysystropus rohweri Ckll. 



but the venation agrees better with that of Systropus, differ- 

 ing, however, as follows : 



(1.) The lower half of the cross-vein from the bend of R 4 to 

 R 2+3 is present, and very distinct, though the upper half is 

 wanting. This vein is absent in Systropus (though the abrupt 

 bend remains to indicate where it was), but is complete in 

 Pantarbes and Exoprosopa. 



(2.) The first posterior cell is closed just before the margin 

 of the wing, a condition approximately intermediate between 

 that of Systropus (in which it is open) and Pantarbes. 



(3.) The anal cell is closed just before the margin, as in 

 Ocondocera (N. Am. Dipt., f. 82). The venation is very well 



