262 Geological Survey of California. 
although all the species, with a single doubtful exception, are peculiar to 
California, and that species is referred to one described from No. 4 2 
New Jersey and Tennessee. 
last-mentioned ranges were uplifted and metamorphosed after the close of 
the Jurassic period, we have not positive evidence that this took place 
prior to the Cretaceous epoch. Still, combining all we know of the 
geology of New Mexico and Nevada Territory, there appears to be little 
doubt that the system of the Sierra Nevada extends over a consider- 
able area, east and west, embracing a number of nearly parallel ranges 
of mountains, some of which, indeed, are little inferior in extent and ele- 
vation to the Sierra Nevada proper. 
e have recognized at least three distinct periods of upheaval and 
metamorphic action in the coast-ranges. The main one was at the close 
of the Cretaceous epoch ; the next in importance was after the deposition 
of the Miocene tertiary—or, at least, of a group of strata which, for the 
present, may be referred to that age. The next in age is a system of east 
and west upheavals, which took place at the close of the Miocene; am 
the third is one which appears to have commenced during the later Plt 
ocene, and to be still going on. 
_ Itisa very interesting fact, that the exterior of the coast-ranges—that 
is to say, the mountains nearest the Pacific—are of earlier date, or older 
- geolo yy the interior ones, or those which border the Sacra 
mento and San Joaquin valleys. This is a repetition on a smaller scale 
of what has_ the course of events in the formation of the whole 
hl hal } first marked 
continent, the exter having out, and the interior 
~~, 
