viua, 6 Pratt and Smith: Petroleum Resources 327 



found in the limestone which forms the ridge along the western 

 coast of the peninsula. 



Fossils collected at locality Uh- 



Cypraea sp. indet. Cerithium sp. indet.; large internal 



Area nodosa K. Mart. (?) cast. 



Schizaster sp. 



Along the western coast from Ayoni north to Catanauan, this 

 limestone is found in the coastal ridge, and occurs conformably 

 only a short distance above beds which clearly belong to the Vigo 

 shale. A short distance inland from Ayoni similar limestone 

 occurs above the Canguinsa sandstone, and is overlain at places 

 by the Cudiapi sandstone. This relation suggests that the lime- 

 stone at Ayoni is the Lower limestone, but the evidence is not 

 conclusive and either limestone horizon may be represented by 

 the fossils from this locality. 



Fossils collected at locality 59. 



Pyrula gigas K. Mart. Pecten leopardus K. Mart. 



Balanus sp. 



The limestone in which these fossils were found occurs on the 

 top of a hill; below the limestone, with a concealed interval 

 between, the Canguinsa sandstone was observed. The thick- 

 ness of the concealed beds is hardly great enough to include 

 the Cudiapi sandstone and the Lower limestone in their usual 

 thicknesses. The fossils, therefore, are assigned to the Lower 

 limestone, although they may represent the Upper limestone 

 instead. 



A sample of limestone (fossil locality 25), which certainly 

 came from the Lower limestone horizon, was collected near the 

 Cabongahan-San Narciso trail at an elevation of 180 meters, on 

 the east side of the ridge extending northwest from Mount Cam- 

 bagaco. Thin sections of this rock show small fragments of 

 limestone and the well-known alga, Lithothamnium ramosissi- 

 mum Reuss, intermingled in a cement of calcite. 



Plates II and III are photographs of typical fossils from the 

 Malumbang series. Plate II represents the Upper limestone and 

 the Cudiapi sandstone, while Plate III shows fossils from the 

 Lower (?) limestone. 



The most conclusive evidence as to the age of the Malumbang 

 series is found in the Lower limestone, which, on the basis of the 

 fossil Lithothamnium ramosissimum Reuss (fossil locality 25) 

 may be assigned to the Miocene. The upper beds in the series 

 are apparently as young as the upper Miocene or the Pliocene. 

 The formation is similar to the "etage marneux" which Ver- 



