46 University of California Publications in Geology [Vol.11 



page 



Occurrence and lithology 81 



Fauna of the San Lorenzo series to the west of Mount Diablo 81 



Comparisons of fauna of San Lorenzo west of Mount Diablo with that 



found in the lower part of the Monterey of the same area 82 



Possibility of faunal zones in San Lorenzo to the west of Mount Diablo 82 



San Lorenzo series to the north of Mount Diablo 83 



General statement 83 



Markley formation 84 



Lithology 84 



Probable relation to Kreyenhagen shale 86 



Fauna 86 



Kirker formation 83 



Disconformity 86 



Lithology 87 



Fauna 88 



Summary of San Lorenzo section on north side of Mount Diablo 89 



List of species from San Lorenzo beds to north of Mount Diablo 89 



Relation of San Lorenzo beds north of Mount Diablo to those to the west 92 



Complete list of species from San Lorenzo series in region of Mount Diablo .... 95 



Statistical summary of faunal list 98 



Review of occurrence of beds referable to the San Lorenzo series at other 



localities in California 99 



San Lorenzo beds in Napa County 99 



Kreyenhagen shale of Coalinga district and to the north 99 



San Lorenzo of San Emigdio Hills 100 



San Lorenzo formation of the Santa Cruz Mountains 100 



Other localities _ 101 



Correlation • 101 



Relation of fauna of San Lorenzo series of the region of Mount Diablo 



to that of the San Lorenzo formation of the Santa Cruz Mountains 101 



Relation to Oligocene of Oregon, Washington and British Columbia 102 



Summary of Oligocene sequence in Oregon, Washington and Vancouver 



Island as recognized by different writers up to the present time 103 



Relation of fauna of the San Lorenzo series to that of the Lower Miocene .. 105 



Summary of stratigraphy 109 



Summary of correlation 110 



Description of localities 112 



Literature cited 115 



Descriptions of species 119 



Subkingdom Molluska 119 



Class Peleeypoda 119 



Family Nueulidae 119 



Genus Acila 119 



Aeila gettysburgensis Reagan 119 



Acila muta, n. srj 119 



Aeila muta markleyensis, n. var J 121 



Acila shumardi, Dall 121 



Genus Nueula _ _ 122 



Nueula postangulata, n. sp 122 



Nueula bifida, n. sp 122 



Family Ledidae 123 



