,~)46 TERTIARY INSECTS OF NORTH AMERICA. 



SCIOMYZA? DISJECTA. 

 PI. 9, Figs. 7, 22, 25, 30, 32, 33. 

 Sciomyzat disjecta Scudd., Bull. II. S. Geol. Geogr. Surv. Terr., IV, 758 (1878). 



A second species, apparently of the same genus as the last mentioned, 

 but smaller, is found in considerable numbers in the same Green River beds, 

 although in far less abundance than the last. The wings appear to be propor- 

 tionally shorter than in the last species, with a rather broader space between 

 the veins in the upper half of the wing, indicating perhaps a broader wing. 

 The legs are slenderer, the disparity in the stoutness of the tibia? and tarsi 

 is not so great, and the tarsi are proportionally shorter ; the legs are also 

 as densely, though less coarsely, spined, and a similar delicacy is observable 

 in the hairiness of the body. All the specimens are preserved on a side view, 

 and like the last species are in a fragmentary condition. 



Length of body of an average individual, 3.2 mm ; of head, 0.55 mm ; of 

 thorax, 1.2 mm ; of abdomen, 1.8 mm ; of wing, 2.4 mm ? ; of hind femora, 1.2 mm ; 

 of hind tibiae, 1.4 mm ; of middle and hind tarsi, l mm . 



Green River, Wyoming. Numerous specimens by the same as the last 

 species. 



SCIOMYZA? sp. 

 PI. 10, Fig. 5. 



Another species of Sciomyza, or perhaps of the same genus as the last- 

 mentioned species (for several of its features are certainly repeated here), 

 seems to be represented by the insect figured in PI. 10, Fig. 5, which is of 

 about the size of S. manca, but is more delicate. It is however so imper- 

 fect as far as the head and wings are concerned that one can not characterize 

 it satisfactorilv without better material. 



Green River, Wyoming. One specimen, No. 18 (Dr. A. S. Packard). 



