DIPTERA CHIIIONOMIIU:. 581 



middle tibia-, i).! mm ; hind tibia?, 1.4 nim ; fore tarsi, 1.8 mm : middle tarsi, 

 _'.:;""": hiinl tarsi, 2.1 nim . 



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



CuiSONOMUS sp. 



Cliironomui up. Scudd., Bull. U. S. Geol. Geogr. Surv. Terr., IV, 749 (1878). 



x 



A minute specimen apparently of this family. Unfortunately it ha- 

 no wings, and little can be said of it more than to record its occurrence : it 

 is :!""" long, has large eyes, a stout thorax, and altogether resembles a Chi- 

 ronomus : it is however distinct from any found in the White River shales. 



Green River, Wyoming. One specimen, No. 141 (F. C. A Richardson). 



CHISONOHIIUB sp. 



I 'I. 5, Figs. 32, 33. 



An indeterminate species of this family, whose generic affinities can not 

 l.c discovered from the entire absence of neuration in the wings and the 

 loss of every other characteristic feature, presents a side view of the body 

 with fragments of legs. The insect is minute, measuring but '2.75 mm long. 

 It may possibly belong to the Ceciclomvidse. 



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



CHIBONOHIDJB sp. 



PI. 5, Fig. 24. 



Another similar specimen, but distinct from the above, exhibits a dor- 

 sal aspect, and little 'iesides the trunk is left. The thorax is comparatively 

 stout, the head nearly as broad as the thorax, and the abdomen very slender 

 and equal. The body is .",. :>;>""" long. 



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



CHIRONOMID.* sp. 



A third indeterminate species probably belongs to this group, but the 



specimen is too imli>tinct to lie of much value. It is a female. The an- 

 tenna' are a little longer than the head, the head a little narrower than the 

 abdomen, the latter tapeiing to a point. The co.-ta o| one \\ing is present 

 and the rather short and moderateh stout leg> of the opposite >ide. 



Length oi body, 1.8' : of middle t'emin ' : of same tibi.-e. 



I-'O-M! ( 'am.n. White Ui\er. I'tali \\ . l>eiitoni. 



