618 PROCEEDINGS OF THE NATIONAL MV8EVM. vol.52. 



2. ARGIA EMMA Kennedy. 



Common. Exuviae numerous about the roots of trees overhang- 

 ing the water, 



3. ENALLAGMA CARUNCULATUM Morse. 



Common. 



4. I3CHNURA CERVULA Selys. 



Abundant in sedgy spots. Local in its distribution. 



5. OPHIOGOMPHUS MORRISONl NEVADENSIS Kennedy. 



This was the first place I took this large yellow OpMog&mphus. 

 It was associated on the riffles with the next species, the two species 

 having identical habits. I saw a female ovipositing on a riffle, 

 striking the water with her abdomen as she flew along (see p. 536). 



G. ERPETOGOMPHUS COMPOSITUS Hagen. 



This widely spread species occurred sparingly on the riffles of the 

 lower Truckee. The males appeared to be more nervous and more 

 touchy, flying farther for conflict with passing males than the males 

 of plnogom.phus morrisoni nevaden&is. 



7. AESHNA MULTICOLOR Hagen. 



Abundant. One pair caught. 



8. MACROMLV MAGNIFICA Mc Lachlan. 



Several were observed on the river. At 5 o'clock in the afternoon 

 a male and female were seen patrolling the road at the agency. The 

 male was taken. 



9. LIBELLULA PULCHELLA Drury. 



Several seen along the river. 



10. SYMPETRUM CORRUPTUM (Hagen). 



Abundant. This species oviposits in the shallow edge of the river, 

 the male holding the female. She taps the water from one to six times 

 in close succession, then the pair fly 50 to 100 feet farther to the 

 next shaUow, this proceeding sometimes covering several hundred 

 feet of shore. The female also oviposits alone, when she takes a 

 much shorter flight, striking the water more frequently. The males 

 were most abundant about the water, but the females were met in the 

 fields or anyvvhere. 



11. SYMPETRUM PALLffES (Hagen). 



The least common of the three species of Sympetrum. 



12. SYMPETRUM SEMICINCTUM (Say), 



Common along the agency ditch. 



PYRAMID LAKE, NEVADA. 



Pyramid Lake, at an elevation of 3,880 feet, with the exception of 

 its twin, Winnemucca Lake, is the lowest of the several saUne lakes 

 which occur in the Nevada Basin and constitute the remnants of the 

 once great Lake Lehontin. Pyramid Lake is even yet a great lake, 



