ACADEMY OF SCIENCES. 73 



VIII. The Northern Sierra Nevada. 



The whole remainder of California lying- east of the Sacramento valley and 

 of the lonijitude of Mt. Shasta, (about 122^ west) may be considered as belong- 

 ing to thi-i region, although it includes ten or more lakes which have no outlets, 

 and therefore belong to the system of interior basins. Yet Pit River, heading 

 very near the eastern boundary line, flows through all obstructing ranges into 

 the Sacramento, showing a general fall of level towards the west, and Lake 

 Tahoe, Lat. 39°, is the only body of water with an outlet running eastward 

 from near the boundary line. The length of this region, north and south, is 

 278 miles, with a width of 85 miles near Lat. 38° 30', and 125 north of the 

 Sacramento Valley, Lat. 40° 30' to 42^. The mountains are lower than in 

 the Southern Sierra, the passes near the lower end being about 8,000 feet high, 

 and diminishing to 4,500 at Lat. 41°, where Pit River cuts the principal ridge. 

 The highest peaks south of this latitude do not exceed 10,000 feet, though Mt. 

 Shasta, north of it, rises to 14,440, or nearly that of the peaks in Lat. 36°- 

 37°. There are less extensive snow fields in summer, njore gener'ally diffused 

 forest, arid more abundant streams of water. 



I spent twenty days in the month of September, 1863, collecting near the 

 summits in Lat. 39° from an elevation of 5.000 to 8,000 feet, and at Lake Ta- 

 hoe, which is 6.083 feet above the sea. The results, of this short visit were 

 highly interesting, adding sixteen species to the known fauna of California, of 

 which four or five were new. (See " Additions," etc., in this Vol., p. 3.) 



I have also visited the foothills in August, up to an elevation of about 

 3.000 feet, but too briefly to obtain any very important facts. It would 

 be premature to attempt to enumerate the animals characteristic of this re- 

 gion, or limited by it in their range north and south. It may be assumed 

 that nearly all those of the three higher classes found in California, but not 

 mentioned in the preceding lists as limited by certain bounds toward the 

  south, are to be found either in this region or the Sacramento Valley, with 

 the exception of the exclusively marine species. This leaves for these two 

 regions, of Mammals, 80, Birds, 253. Reptiles, 34, Batrachia, 15. supposed to 

 inhabit the northern half of the State, excluding the sea-coast. The marine 

 species, probably found along our northern coast, are 12 Mammals and 48 

 Birds. Five species of fish are'known, and there are probably more, inhabiting 

 the mountain lakes and streams exclusively. 



Local Faunas. 



It would be useless and unimportant to give lists of all the animals observed 

 or collected at the several points where collections were made ; first, because 

 my residSnce at each was not long enough to determine all those to be .found 

 there at various seasons ; and secondly, because most of the points were too 

 near together to furnish peculiar species. Two localities, however, are interest- 

 ing enough in this respect to authorize a special list of their vertebrate animals. 



Pkoc. Cal. Acad. Sci., Vol. IV.— 6 Feb. 1870. 



