NO. 2192. DRAG0NFLIE8, CALIFORNIA AND NEVADA— KENNEDY. 529 



minute (in obscurus on segments 2-9, and only that on segment 2 

 developed) . 



Length of abdomen, 18 to 20 mm.; width of abdomen, 7; length of 

 hind femm-, 4. 



10. THE WESTERN SPECIES OF OPHIOGOMPHUS, INCLUDING A NEW 

 SPECIES AND TWO NEW VARIETIES. 



Ophiogomplius is a genus in which nearly all of the species live on 

 streams or lakes which have gravelly beds or beaches. Because of 

 this preference of OpMogomphus in the matter of environment nearly 

 all of the species are restricted to either the Appalachian region or to 

 the mountainous portions of the western half of the United States. 

 In Muttkowski's catalogue six species ^ are listed from this western 

 region. In my collecting during the past two summers I have taken 

 aU these six species except montanus, and phaleratus, which Prof. J. G. 

 Needham described from a single male captured on the Willamette 

 River of Western Oregon.^ The mdividuals of OpMogomphus, while 

 apparently emerging in considerable numbers, are scarce and seldom 

 found except on gravel bars or gravelly rapids, which are places 

 usually avoided by collectors. Occasionally the odonatist stumbles 

 onto a place where a single species is very abundant. Severus was 

 abundant on Satus Creek, in Yakima Comity, Washington. Occi- 

 dentis was abundant in the two acres of sagebrush at the mouth of the 

 Umatilla River in Oregon, and morrisoni was common on the north 

 beach of Doiiner Lake, California. But during the more than three 

 months of actual field work, the most of which was spent on streams, 

 a half dozen specimens of OpJiiogomplius after having walked 6 or 7 

 miles of stream was considered a good days catch. 



The imagoes of the various species spend the greater part of their 

 time seated on gravel bars from which they fly up at intervals to catch 

 insects or to intercept individuals of their own kind. They are rarely 

 found far from running water. 



Copulation is a lengthy affair. The male usually captures the 

 female as she flies along the water's edge on her business of oviposi- 

 tion, when he grasps her head with his feet and then, bending his 

 abdomen forward, grasps her occiput with his claspers while freeing 

 his feet. She in the meantime bends her abdomen forward and copu- 

 lates. After a short nuptial flight the pair settles on some bush and 

 remains in copulation many minutes. In ovipositing the female 

 deposits the eggs in swift water, usually on rapids, where she flies 

 back and forth dipping the tip of her abdomen in the stream. Though 

 the eggs are laid on the shallow rapids, the nymphs during the latter 

 part of their life live in the muddier bottom of the quieter water, for 



1 Sequoiarum was described by Miss Butler in Can. Ent., vol. 46, 1914, p. 346, but is a synonym o! bison. 



2 Since arriving at Cornell Uaiversity I have examined the type of phaleratus and find it to be a form 

 of occidentis. 



65008°— Proc.N.M. vol.52— 17 34 



