;^Q CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



10° to the east. The lowermost member as exposed in this 

 cliff-section is an oyster bed made up almost wholly of the 

 remains of Ostrea lurida. Resting upon these oyster beds is a 

 bed of flesh-colored clay containing numerous specimens of 

 Corbula fragilis Hinds. These Corbula beds (Cal. Acad. Sci. 

 Loc. 563) are in turn overlain by sandstone and a prominent 

 conglomerate member whose pebbles are composed of schist, 

 chert, sandstone and granite. Two hundred yards northeast 

 of the headland, lignitic sands containing wood and pine 

 cones, oyster shells and Chione undatella, rest upon a con- 

 glomerate which dips 1° to 2° to the west. These horizontal 

 lignitic beds exhibit a striking relation to the underlying 

 conglomerate in that roots of pine trees have penetrated 

 the contact between the two formations, thus indicating in 

 quite conclusive manner, a notable Pleistocene unconform- 

 ity. These lignitic beds and the. overlying tan-colored sand- 

 stone conglomerates are assigned to the Tomales formation. 

 The pine cones are not badly damaged and do not show 

 wear by running water or by waves. They have been iden- 

 tified by Miss Alice Eastwood, Curator of Botany, California 

 Academy of Sciences, as Pimis radiata. These cones, as well 

 as Chione undatella, indicate a climatic condition during the 

 upper Pleistocene considerably warmer than that of today. 

 Chione undatella does not range further north at the present 

 time than San Pedro, California, and Pin us radiata- has its 

 present northern limit in San Mateo County. 



California Academy of Sciences Localities 561 and 563 

 are on Millerton headland, so that both characteristic Pleisto- 

 cene faunas are present in the one vicinity. The base of the 

 Millerton formation is not exposed at the type locality, the 

 block making Millerton headland being lodged between two 

 fault lines of the San Andreas Rift. On the north side of 

 Tom's Point near the entrance to Tomales Bay, basal beds of 

 the Millerton formation rest unconformably upon Franciscan 

 chert and glaucophane schist. The basal member is a conglom- 

 erate composed of fragments of chert, schist, tuff and tuff- 

 breccia, and its matrix is a dark gray andesitic mud. Pieces of 

 bark, a sixteen-inch tree trunk and cones of Pinus radiata are 

 imbedded in it. California Academy of Sciences Locality 412 

 is in sandy shales overlying the basal conglomerate. These 



