OPHIOGOMPHUS 75 
almost altogether on the riffles, but emergence was almost altogether along the 
deeper mud-bottomed pools. In copulation the male sought the female while 
she rested on a stone. Copulation occurred immediately after the male grasped 
the female. The latter would rest on a stone in a riffle and every few seconds 
make a short flight, striking the tip of her abdomen on the surface of the water 
Just once, when she would rest for a few seconds on a stone and repeat the 
process. These short flights were repeated five or six times in succession. By 
August 1 many individuals showed age in the frayed wings, the olive coloration, 
and in their difficulty in standing. Frequently when one would attempt to alight 
on a stone it would fall over on its side or tumble on its head. During the first 
part of their season they were most abundant on the gravel bars, but during the 
oviposition period they were most abundant about the riffles. 
17. Ophiogomphus montanus Selys 
Selys ’78, p. 480: Mtk. Cat. p. 84. 
Length 54 mm. Expanse 64 mm. Mont. 
A greyish green western species, faintly striped with brown. Face and 
occiput greenish, the latter without horns and with a touch of black on its 
outermost angles. Thoracic stripes of the first pair narrow, parallel sides, 
separated by the pale carina. Stripe 2 broader and well separated from 3, which 
is of equal breadth, but tapers downward. Stripe 4 obsolete above the spiracle, 
cross connected at the spiracle with the lower end of 5 by two narrow curved 
lines; 5 continuous but narrow. Legs brown, pale on base of femora, and outer 
side of tibiae. Wings hyaline, stigma tawny. The pale middorsal line on the 
abdomen is reduced to elongate triangular spots on the middle segments, and to 
small round spots on 7 and 8 and 9; 10 wholly pale. The slightly dilated side 
margins of segments 6 to 9 are yellow; 6 and 7 black margined. Appendages 
yellow. 
18. Ophiogomphus morrisoni Selys 
Selys ’79, p. 65: Mtk. Cat. p. 84: Kndy. ’17, p. 534: ’15, p. 336. 
Var: neva@ensis Kndy. 
Length 50 mm. Expanse 68 mm. Nev., Calif. 
This is a large grayish green species obscurely striped with brown, having 
the legs brown and yellow and the abdomen chrome yellow ringed with black. 
Face and hornless occiput yellow, the latter touched with black on its outer- 
most angles. Thoracic stripes of the first pair narrow, barely reaching the collar 
below; stripe 2 broad, abbreviated and isolated above and mostly separated 
from 3 except at lower end; stripe 3 widened above, confluent with 5 above and 
4 below; stripe 4 present only below level of spiracle; stripe 5 narrow, complete. 
Legs yellow at base, on femora beneath and toward base and on tibiae; else- 
where black. Abdomen yellow with middorsal and lateral rows of broad yellow 
spots, the dorsal row club-shaped on 2-9 and narrowing to rearward, the lateral 
spots linear, marginal, and notched by a black spot at the hind angle on 3-8; 
9 is all yellow at the side and the side spot of 10 is confluent with the dorsal spot 
around the hind margin. 
