198 GEO. n. HORN, M. D. 



Notes on the COLEOPTEROUS fauna of Gnadalnpe Island. 



BY GEORGE II. HORN, M. D. 



The small collection of Coleoptera to which these notes refer, was 

 made by Dr. Edward Palmer, during the spring and early summer of 

 1875, who at the same time collected a full representation of the flora 

 of the island. The island of Guadalupe is in the Pacific Ocean about 

 one hundred miles westward of the coast of the peninsula of Lower 

 California, and (from the maps) slightly N. W. of the point of cross- 

 ing of the 28° North and 118° West, and is therefore bathed in the 

 Alaskan current which renders the climate of the western coast of 

 North America as far south as the extremity of the Californian penin- 

 sula cold and foggy during the greater part of the year. 



The similarity of the climate of the regions immediately adjacent 

 to the ocean, causes a remarkable unity of fauna as far as Coleoptera 

 are concerned, and numerous species extend their range from Alaska 

 to Cape San Lucas, while others extend over large portions of the 

 same region. The islands adjacent to the coast are exposed to the 

 same climatic influences and the fauna should therefore be entirely 

 similar, and as far as the islands have been explored comparatively 

 few new species have been discovered, and on Guadalupe island alone 

 has a new genus been discovered. The species of Coleoptera with few 

 exceptions belong entirely to the fauna of California proper, and are 

 in no way allied to that of Lower California. 



The faunal (Coleopterous) regions of the west coast of North 

 America are worthy a few notes in this place. The cold Alaskan 

 current of which mention has been made influences the fauna of the 

 regions adjacent to the coast, this may be culled one fiiunal region, 

 extending with a slight interruption at San Diego, from Alaska to 

 Cape San Lucas. The range of mountains adjacent to the coast in 

 this entire extent limits the region to the eastward. The great central 

 valley of California extending northward into Oregon, limited on the 

 west by the coast range and on the east by the Sierra Nevada with a 

 southern limit near Fort Tejon, forms a tolerably well marked faunal 

 region. The San Diego region extends southward along the eastern 

 side of the peninsula of California, eastward into Arizona and to the 

 north (east of the Sierra Nevada) to Owen's Valley, and following the 

 Colorado river indefinitely toward Nevada and even into Utah. North- 

 ern and eastern Oregon and Washington Territory appear to be a 

 middle ground on which we find species from Hudson's Bay, Cali- 



