548 TERTIARY INSECTS OF NORTU AMERICA. 



HETEROMYZA DETECTA. 

 PI. 5, Fig-. 70. 



Hetwomysa detecta Scudd., Bull. U. S. Geol. Geogr. Surv. Terr., Ill, 7">8-759 (1877). 



A single specimen and a very poor reverse of it occur on the same 

 stone with Spiladomyia simplex. Both wings and the thorax are preserved, 

 with short fragments of moderately stout hairy legs. The venation is 

 obscure, and the species referred provisionally to Heteromyza until better 

 specimens decide more certainly to which of the groups of Muscidse it belongs. 

 So far as it can be determined the venation is very similar to that of the pre- 

 ceding species, but the wing is much smaller, and there is a peculiarity about 

 it which is not quite clear: at the bend of the costa, indicating the termina- 

 tion of the auxiliary vein, there is a short, distinct, oblique cross-vein nearly 

 in continuation of the base of the costa, but bent slightly downward, which 

 reaches the first longitudinal vein; the latter runs close to the costa and 

 strikes it about midway between the tip of the auxiliary vein and the tip of 

 .the wing; the costa apparently runs exactly to the tip of the second longi- 

 tudinal vein; the third and fourth longitudinal veins run parallel to each 

 other to a very little way beyond the extremity of the auxiliary vein, where 

 they are united by a short cross-vein, beyond which they both diverge from 

 each other in opposing curves, equally turned aside from their former course; 

 the third longitudinal vein runs to the tip of the wing; the fourth is united 

 half-way to the border of the wing by a long oblique cross-vein, running at 

 right angles to the fifth longitudinal vein. The extremity of the basal cells 

 apparently lies about half-way from the base of the wing to the tip of the 

 auxiliary vein, but this point is very obscure. 



Length of wing, 1.65"""; breadth of same, O.i)5" mi ; length of thorax, 

 0.75"""; breadth of same, O.f>. r )""". 



Chagrin Valley, White River, Colorado. One specimen (W. Denton). 



Family ANTHOMYIDvE. Robineau-Desvoidy. 

 ANTHOMYIA Meigen. 



ANTHOMYIA INANIMATA. 



PI. 3, Fig. 19. 

 .liilliiniiiiin iiiidiiiiKilii Scudd., Uep. Progr. Gool. Surv. Can., 1875-1876.273-274 (1877). 



This species is pretty well represented by a single individual and its 

 reverse, showing the superior view of the insect with the wings (excepting 



