SOUTHERN CALIFORNIA ACADEMY OF SCIENCES. 151 



maintenance the Big Trees have apparently not increased their 

 range since the glacial epoch. They have only just managed 

 to hold their own on the little strip of country where the cli- 

 mate is locally favorable." 



It will be seen by the foregoing list that the extinct flora 

 of California is almost exclusively Miocene and Pliocene, with 

 an occasional species from older formations. This might rea- 

 sonably be expected when we consider the comparatively recent 

 period of the appearance of California above the ocean. 



While California formed a part of a bed of the Pacific Ocean 

 and supported innumerable forms of marine life, large areas 

 east and north of it were clothed with extensive forests, which 

 furnished shelter and food for the many genera and species of 

 strange vertebrate animals not found in our own strata. 



From the recognized affinity between the flora of North 

 America and that of the Arctic Regions, it is inferred that our 

 floras, both fossil and living, had their origin in the North, and 

 from there the forms have been gradually distributed south- 

 ward. This will account for the fact that a large number of 

 species are common to Greenland and North America ; and also 

 accounts for the identity or great similarity of vegetable forms 

 of the above named regions with those of China and Japan. 

 The affinities of the present flora, with those of the middle and 

 later Tertiary are unmistakable, although many of the living 

 genera have not been discovered in a fossil state, and may have 

 been of more recent origin, or later introduction. Many of the 

 fossil forms are not represented here in the living species, but 

 their representatives are now found in distant parts of the world 

 under different climatic conditions from those of the Calif or- 

 nici of tod;iy. 



THE FAUNA OF PREHISTORIC CALIFORNIA. 



Having outlined the geological vicissitudes which brought 

 about and dominated the geography of California from the dawn 

 of the Cretaceous Period, or "Reptilian Age," down to the time 

 when the earth was prepared for man's occupancy, it will be 

 necessary to return to our former starting point, in order to out- 

 line the introduction and succession of animal life in California, 

 and as the Vertebrates are the dominant and most important of 

 the sub-kingdoms, we will give them the most attention. 



The Invertebrates, however, being the oldest and most per- 

 sistent, serve as important, and in fact, indispensable aids in de- 

 termining the geological formations, and their relations to the 

 order of succession of animal and vegetable life through the 

 ages. 



Vertebrates are much more susceptible than invertebrates 



