324 The Philippine Journal of Science 1913 



west coast, the formation is to be found in the region of Mi- 

 najero Bay and north beyond San Andres. Between the mouths 

 of Bahay and Vigo Rivers and farther north near San Narciso, 

 the vicinity of the coast line is made up of littoral deposits. 



At various places over the surface of the littoral formation 

 shells were observed which probably represent the molluscan 

 fauna existing when the benches were below sea level. All the 

 species identified are still living, and many of them are edible. 

 Numerous deserted kitchen middens are encountered near the 

 coast, and it is possible that some of the shells collected came 

 from these middens and do not represent the formation upon 

 which they were found. 



The genera and species noted are as follows (Plate I) : 



Spondylus. PotawA6.es sp. 



Conus flavidus Lamarck. Voluta sp. 



Trochus fenestratus Gmel. Natica sp. 



Area cecillei Phil. (?) Crista pectinata Linn. 



Astralium stellare Gmel. Strombus canarium Linn. 



Cerithium nodulosum Brug. Telescopium telescopium Linn. 



Cerithium jenkinsi K. Mart. (?) 



Malumbang series. — The Malumbang series at the top of the 

 column of folded strata consists of the Cudiapi sandstone, which 

 is generally, but not invariably, included between limestones. 

 The limestones are sandy and at many places are either missing 

 or cannot be distinguished from the sandstone which is usually 

 calcareous. They are brownish yellow to white, and generally 

 massive or in thick poorly defined beds. Locally, and usually 

 in the sandy facies, the limestone is bedded, the individual layers 

 averaging from 15 to 30 centimeters thick. 



The Upper limestone is generally coralline, although the tran- 

 sition between it and the calcareous sandstone below is gradual. 

 At places on the coast where it is not highly inclined, it cannot 

 be delimited from the recently raised reefs. In representative 

 exposures it shows a thickness of about 30 meters. 



The Cudiapi sandstone is named from a type occurrence in 

 the summit of South Cudiapi Mountain. In many places it 

 exhibits alternate beds of different thicknesses ; the thinner beds 

 are more calcareous and harder than the intervening thicker 

 beds, and are more resistant to weathering so that the outcrops 

 are characterized by the protruding edges of the thin beds. 

 Where the Lower limestone is missing, the Cudiapi sandstone 

 cannot be separated sharply from the underlying Canguinsa 

 sandstone. The estimated thickness of the Cudiapi sandstone 



