NO. 2192. DRAGONFLIES, CALIFORNIA AND NEVADA— KENNEDY. 575 



vivida may occiu' along the stream for some distance after it emerges 

 onto the more level valley floor. Besides occiirring on all the 

 streams of the Coast Momitains, Octogomjjlius is found on the smaller 

 streams of the west slope of the SieiTas which are perennial but do 

 not rise high enough in the mountams to carry snow water. 



From April to August it is abmidant on the mountain streams 

 west of Stanford University. On June 8 I found it common on the 

 small streams in the gorge east of the Napa Asylum. This record 

 for Napa County, CaUfornia, is at present the northernmost record 

 for the Coast Mountains, though it will probably be found as far 

 north as southwestern Oregon, when that region is explored. On 

 June 15 I found numerous exuviae along the banks of the Chico 

 River, where it emerges from the gorge east of the city of Chico. 

 This pomt, in Butte Coimty, California, is on the west slope of the 

 Sierras and is at present the northernmost record for the species. 

 My southernmost records are from Mr. Fordyce Gruinell's collection 

 in the Southwest Museum of Los Angeles, one being a specimen from 

 the San Gabriel Momitains and the other from the Mount Wilson 

 trail, both in Los Angeles County.^ Calvert^ records this species 

 from Baja or Lower California. 



For a gomphine this species has a very long season, probably the 

 longest season of any of the western gomphines. A teneral male was 

 taken on San Francisquito Creek (Santa Clara County, California) 

 April 20, 1914. Many were seen on Stevens Creek (Santa Clara 

 County, California) May 31, while oviposition was observed on the 

 same stream on July 17 and two old males were captured there on 

 August 16, which is the latest seasonal record for the species. 



The nymphs of this species occur abundantly in the leafy trash 

 which collects in the pools and eddies of the stream. I do not believe 

 that they burrow in the sandy bottom, as I have observed no tracks 

 even where the exuviae showed the species to be very abundant. 

 In June, after the annual emergence, I found two sizes of nymphs, 

 the larger of which was immature and would have emerged the 

 foUowmg season (1915). (See figs. 342-344.) The nymphs in- 

 cluded in the smaller size showed considerable variation in size, but as 

 there was a complete series between the largest and the smallest, 

 I concluded that they were probably from early and late ovipositings 

 of the same year and all would emerge in the second season (1916) 

 (see figs. 342 and 343). This would indicate that the nymphs spend 

 three years in the water. Nymphs taken August 16 had assumed the 

 final stage, in which they wintered to emerge the following season. 

 The emergence takes place previous to May 31, probably occurring 

 (on Stevens Creek, Santa Clara Comity) during the latter half of 



1 In August, 1915, 1 found Octogomphus nymphs in the headwaters of the Mojave River. Since -wTiting 

 the foregoing I have found in Dr. P. P. Calvert's collection an Octogomphus female collected by Prof 

 Trevor Kincaid, July 25, 1895, at Olympia, Washington. 



« Proc. Cal. Acad. Sci., ser. 2, vol. 4, 1895, p. 502. 



