4 CALIFORNIA ACADEMY OF SCIENCES. 



of Santa Barbara, the eastern part of Kern, and the 

 greater portion of Inyo counties. 



To the student who is unacquainted with the topog- 

 raphy and climatic conditions of California, the follow- 

 ing brief sketch of the natural features, more especially 

 of the region under consideration, will be of service. 



The State lies approximately between the parallels of 

 33 and 42 of latitude, and is crossed by two great 

 mountain systems, lying along and in general parallel 

 with its eastern and western borders. The former 

 the Sierra Nevada extends from near the northern 

 border to about the 35th parallel. Its average eleva- 

 tion is from 5,000 to 8,000 feet, but there are occasional 

 ridges of 9,000 and 10,000 feet altitude, and individual 

 peaks that exceed 14,000 feet. The eastern slope 

 descends quite abruptly to the Great Basin, itself 4,000 

 to 5,000 feet above the sea level; the western slope is 

 much more gradual. 



The Coast Range consists, like the Sierra Nevada, of 

 numerous nearly parallel ridges, and extends the entire 

 length of the State. Its general altitude is from 2,000 

 to 6,000 feet. These two systems are united near Mt. 

 Shasta in the north by a series of cross ranges, and 

 again in the south near the northern boundary of Los 

 Angeles County, thus inclosing the great central valley, 

 some 400 miles long and 60 miles wide, drained by the 

 Sacramento and San Joaquin rivers, which, after their 

 junction, find their way to the ocean through a gap in 

 the Coast Range at the Golden Gate. South of this 

 junction of the Sierra Nevada and Coast Range, the two 

 systems are continued as a single one, running in a 

 generally southeasterly direction toward the Colorado 

 River, sending off, however, at about the middle of its 

 length, a branch to the south, known as the San Jacinto- 



