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128 DELOS AND RALPH ARNOLD 
lineata, Chrysodomus tabulatus, Solariella cidaris, and Solariella 
peramabilis, which now inhabit northern waters near shore, but 
which have been dredged in the deep water between Catalina 
Island and the mainland. Z 
The upper San Pedro series is separated from the lower for. 
three reasons: (1) on account of the unconformity existing 
between the two; (@) on account of the difference in their 
lithologic characters, the former consisting of gravels or coarse 
sands, while the latter is made up wholly of rather fine gray 
sands; and (3) because of the great difference in the faunas of 
the two; that of the former being one indigenous to warm water, 
that of the latter, one which is now found living where sub- 
boreal conditions prevail. 
The occurrence of Pleistocene deposits younger than the 
upper San Pedro beds at several points along the coast, and the 
crustal movements and elevation of the coast that have taken 
place at several places since the deposition of the upper San 
Pedro beds indicate that quite a long period of time has elapsed 
since the latter were laid down. 
A raised beach on the north end of Deadman Island (see 
Fig. 1), six feet above sea level and four feet thick affords 
evidence of another period in the Pleistocence. The shells in 
this deposit are the same as those found in the beach at Dead- 
man Island at the present time, and the most of them retain their 
original coloration. This raised beach represents a very late 
Pleistocene horizon. 
Post-Pleistocene Deposits— The marine deposits of Deadman 
Island and the San Pedro terrace are overlain by alluvial 
deposits which contain large quantities of shells in certain 
places. These shell heaps are ancient Indian kitchen middens. 
Shells of a kind that would be used for food, such as Halotis 
cracherodit, Pecten equisulcatus, Chione succincta, Tivela crassatel- 
loides, Tapes staminea, Saxidomus aratus, and others are found 
mixed with pieces of charcoal, flint chips and animal remains 
in these ancient accumulations. These Indian kitchen middens 
are often mistaken for fossil deposits, especially the one at Port 
