288 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.49. 



ARGIA VIVIDA Hagen. 

 Figs. 31-34, 37-38, 45-47, 49, 52-53, 62-64, 71-76. 



The second half of this section deals with Argia vivida and includes 

 a description of its nymphs. Argia emraa and Argia vivida are the only 

 Argias I have found in the Columbia watershed. 



Argia vivida has been found in thi'ee localities, all of which agree in 

 certain particulars. 



In June I made a four days' drive to the falls of Logic Creek, which 

 is the main tributary of Satus Creek. I succeeded in getting down 

 to Logie Creek in two places and down to Dry Creek, which is the 

 main tributary of Logie, in one place. This is an exceedingly difficult 

 region to explore in a buggy. The single wagon trail runs up hill for 

 60 miles, follo\ving the surface of the ancient slope, with the creeks 

 rushing down tlirough canyons 500 feet below the level of the road. 



On June 15 I found Argia vivida very abundant on an area of not 

 over an acre in extent about 15 miles above the mouth of Logie Creek. 

 The road at this place went down into Logie Canyon through a short 

 lateral ravine. The bottom of the canyon opened out at this point, 

 making a small flat of about 2 acres in extent, which was covered with 

 grasses, with here and there scrub oak trees, and along the creek its 

 usual line of alders, back from which stretched thickets of rose and 

 sumac bushes. At one end of this flat a spring oozed out at the base of 

 the cliff, and its stream, trickling down through the alder thicket, con- 

 tained many vivida nymphs. The shade, as usual in an alder thicket, 

 was dense, but Argia vivida in couple were resting in profusion on the 

 bushes, dead brush, and rocks, which filled this stream. Tenerals 

 were numerous as well as males in high color and a few females in full 

 color, but I saw none copulating or ovipositing. This spring stream 

 was not over 100 feet long, and its bed and sides were of black muck, 

 from the leaves which fall into it annually. Scattered over the bed 

 were rounded stones up to 12 inches in diameter, to the under sides of 

 which the vivida nymphs were clinging. The spring water was cold 

 and the nymphs were sluggish. Exuviae were found clinging to the 

 stones but an inch or two above the surface of the water. Argia 

 vivida is a comparatively sluggish insect and seemingly very local or 

 restricted in its choice of environment. Argias were very abundant 

 on the ground in the open spaces of the flat near this spring stream, 

 but were not found farther than 150 feet from it. In couple they 

 hung to bushes when hovering about the stream, because the bushes 

 overhung the water, giving them little choice, but outside in the sun- 

 shine they sat mostly on the bare ground or on stones or sticks 

 lying on the ground. They were easily taken by approaching care- 

 fully and slapping the net over them or scooping them with the net. 

 They were associated here with Sympetrum madidum and an Aeshna, 



