620 PROCEEDlNGii OF THE NATIONAL MUSEUM. vol.62. 



4. SYMPETRUM CORRUPTUM (Hagen). 



This species is abundant all over the West, except above 5,000 

 feet. But here it fairly swarmed, occurring in far greater numbers 

 than I had seen it an.ywhere else. Its exuviae hung on driftwood 

 along the beach several deep. 



HUMBOLDT RIVER, CARUY, NEVADA. 



August 6 to 10 was spent in a hurried trip up the Humboldt River. 

 This strange river rises in the mountains on the east side of Nevada 

 and runs west nearly across the State to flow out onto the Humboldt 

 Flats, where it forms a large shallow lake called Humboldt Sink. 

 Humboldt Sink is surrounded by miles of snow-white alkali flats. I 

 did not get to it. The Humboldt River runs through a region of low 

 mountains barren of vegetation except sagebrush and its usual ac- 

 companiments. The river is alkaline in most of its lower course and 

 is strange in that no trees whatever grow along its banks. Instead, 

 there are great stretches of dense thickets of slender wiUows, called 

 "pin willows" by the cow punchers of the region. As these grow up 

 to the edge of the pei-pendicular clay banks of the stream, following 

 the course of the stream on foot along the bank for any distance is 

 almost impossible. Humboldt River has the same fauna as the lower 

 Ti'uckee, the only other stream of the Lehontin Basin examined. 



llie river at Carlin, which was the farthest upstream examined, 

 flowed over continuous gravel beds. In the bottoms were several 

 sloughs from waste irrigating water. I collected here on August 6. 



1. LESTES CONGENER Hagen. 



Abundant . 



2.ARGU EMMA Kennedy. 



Occasional on the river banks. 



3. ENALLAGMA CARUNCULATUM Morse. 



A few seen on a slough. 



4. ISCHNURA CERVULA Selys. 



Common about the sloughs. 



5. ISCHNURA PERPARVA Selys. 



AV)out the sloughs. 



6. OPHIOGOMPHUS MORRISONI NEVADENSIS Kennedy. 



Several caught on the gravel bars, but collecting made difficult 

 by a large flock of killdeers which flew ahead and disturbed the 

 dragonfhes. 



7. ERPETOGOMPHUS COMPOSITUS Hagen. 



Three males caught. 



8. AESHNA PALMATA Hagen. 



One male taken. Several seen among willow thickets near the 

 sloughs. 



9. UBELLULA FORENSIS Hagen. 



Several seen. 



