164 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4TH Ser. 
disturbances during that age have been profound and far- 
reaching, they were longitudinal. There was here, as else- 
where in the northern hemisphere, a gradual drop from the 
subtropical warmth of the Eocene to the cool climate of the 
Pliocene, the chill of the Glacial Epoch, and then a fluctuating 
rise to the genial climate of the present. This has been 
recorded in the successive marine faunas, but the changes were 
so gradual that during the Neocene there was no catastrophic 
destruction of the inhabitants of the sea. From each geologic 
formation many species live on into the next. It would have 
delighted Lyell.to see such a complete illustration of the prin- 
ciple he adopted for the subdivision of the Tertiary, for here 
we have a gradation from the Eocene with no living species, 
through the Miocene and Pliocene with gradually increasing 
number of modern forms, the Quaternary with about 90 per 
cent of recent species, to the present, where in the same region, 
out of a marine fauna of somewhere near a thousand species, 
over four hundred extend back into the Quaternary, and nearly 
a hundred extend back into the Tertiary. 
TABLE OF MIOCENE FAUNAS OF CALIFORNIA. 
EtcHEGOIN fauna, of the Coalinga region, of the Salinas and the 
a San Benito valleys. 
Fy PMR ec RADAR AN eR A ete eA UAE oe 8 
“ — | San Pasro-Santa Marcarira faunas, of the Mt. Diablo region, 
= Salinas valley, and the Coalinga region. 
{x} ee ee eee Eee eee 
5 MontTEREY-TEMBLOR faunas, of the Contra Costa hills, Mt. Ham- 
= ilton Range, Black Mountain, Santa Lucia Range, Coalinga 
= | & region, Bakersfield region, Santa Ynez and Santa Monica 
ES mountains, and Santa Ana Range. 
4 
Vagueros fauna, of the Santa Lucia Range, Black Mountain, 
the Santa Monica and Santa Ynez mountains. 
As shown in the table, there are only two major faunal divi- 
sions of the Miocene: a lower, including the Vaqueros and 
the Monterey-Temblor faunas; and an upper, including the 
San Pablo-Santa Margarita and the Etchegoin faunas. 
The entire Miocene fauna consists of about 300 species 
described, and of these about 220 are confined to the Miocene. 
The entire lower Miocene, as known as present, consists of 
about 173 species, of which 116 are confined to lower Miocene, 
25 range into upper Miocene; 11 range into Pliocene; 1 ranges 
