NEOCENE STRATIGRAPHY. 345 



In summary, it will be seen that of 104 species iden- 

 tified 99 or 95% are living. But many of these living are 

 only known now in, for example, the Arctic fauna; thus 

 it is found that of the 104 species, 26 have not been re- 

 ported from San Pedro, leaving 78 species of 104 fossils 

 species known to be living or 75%. Even supposing that 

 a better knowledge of the fauna should reduce by one- 

 half the number not known there at present, we should 

 still have only 87% of the fossil fauna represented in the 

 living. Again notice that of the species which have mi- 

 grated all but two have gone northward, a number being 

 known only in Arctic waters at present. As indicated in 

 the last column a number of these northern forms are 

 still found on Catalina Island. But as has been shown 

 by Professor Lawson,* Catalina Island did not share in 

 the subsidence of which we have such abundant evidence 

 at San Pedro and all along the coast. Having in mind 

 then that these beds lie on what are apparently wind de- 

 posits, and are overlaid by beds whose fauna differ mark- 

 edly from that of these beds, but agrees very closely with 

 the present fauna of the coast, also that the hill presents 

 evidence of having been almost or completely submerged, 

 we seem justified in drawing the following conclusions: 



ist. The deposition of these beds has been followed 

 by a submergence of at least 1200 to 1400 feet, and later 

 has come uplift to the present level. 



2d. That there has been a change in the climate from 

 cold to warmer. 



3d. That these changes have occupied a long time, as 

 judged by the fact that so few of the migrating forms have 

 become extinct; and by the extent of wave erosion ex- 

 posed on the hill. 



Based on the above, the following suggestion is made : 



* Uuiv. of Gal., Bull. Dept. GeoL, yoI. i, p. 138. 



