632 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.52. 



SOUTHERN SIERRA NEVADA MOUNTAINS. 



The following list is compiled from sources as follows: 



Records on specimens in the collection of the California Academy 

 of Science. 



Records on specimens in Mr. Fordyce Grinnell's collection in the 

 Southwest Museum of Los Angeles. 



From a collection sent mo by Mr. and IMi-s. L. R. Reynolds of San 

 Francisco, who had collected in the region of Sequoia National Park. 



From a collection sent me by Mr. G. F. Ferris of the entomological 

 department of Stanford University, who had collected in the region 

 of Yosemite National Park. 



From specimens collected by Dr. J. C. Bradley in the Mount 

 Whitney region during July and August, 1915, and now deposited 

 in the Cornell collection. 



From specimens in the Cornell collection collected by Dr. J. H. 

 Comstock in Tuolumne County and the Sequoia National Park, 

 July 17-24, 1907. 



The species are Canadian and the list agrees with those I collected 

 at altitudes of from 5,000 to 7,000 feet in the region of Lakes Donner 

 and Tahoe (see pp. 611-616 of this paper). The list is also repeated 

 in the series of Canadian species I caught at 4,000 feet elevation near 

 Bend, Oregon,* and agrees with the hst ^ collected by R. C. Osburn. 



As stated at the beginning of these locality lists, the eastern side 

 of the State of California for nearly its entire length is occupied by 

 the great upland of the Sierra Nevada Mountains. This rises gi-ad- 

 ually through a distance of 30 to 50 miles from the Sacramento and 

 San Joaquin Valleys on its west side until an altitude of 7,000 to 

 10,000 feet is reached near the Nevada boundary. Above this tower 

 the great peaks of Lyell and Whitney with their lesser but numerous 

 companions. After reaching this great altitude along the eastern 

 border of the State the Sierra drops suddenly by the greatest escarp 

 in North America to the comparatively low elevation of 3,000 feet. 

 Nearly the entire west slope from 2,000 feet up to 8,000 feet is covered 

 with coniferous timber, which is usually sparse. 



This great Sierra apparently forms a barrier to several Pacific 

 coast species such as Lestes stultus Hagen, Zoniagrion exclama- 

 tionis (Selys), Ischnura erratica Calvert, Cordulegaster dorsalis Hagen, 

 Opliiogomphus bison Selys, Odogomphus speculaiis (Hagen), and 

 Aeshna walkeri Kennedy. To a less extent it shuts interior forms 

 away from the coast, such perhaps as EnaUagma clausum Morse, 

 Lihellula composita Hagen, and Plathemis suhomata Hagen. 



The following list includes the majority of those interesting north- 

 ern species which are able to maintain existence as far south as 



1 Proc. U. S. Nat. Mus., vol. 49, July, 1915, pp. 333-337. 

 * Ent. News, vol. 16, 1905, pp. 184-196. 



