NO. 2107. DRAGONFLIES, WASHINGTON AND OREGON— KENNEDY. 323 



but on tho west side rise the timber-covered Elkborn Mountains. 

 The Powder River winds through the center of tho valley, but after 

 tho first run-off of snow water this stream is hardly more than a 



Figs. 160-1G7.— Agrion aequabile yakima. 100-101. Wings of male and female showing extent 

 OF COLOR. 162. Segment 2 of male. 163. Penis. 164. Male appendages. 165-166. 

 Ntmph. 167. Dorsal view of labium of nymph. 



succession of gravel bare, with but little odonate life. The channel 

 of the river, however, is higher than either side of the valley floor, 

 which makes, on each side of the valley and parallel with the river, 



