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212 The Philippine Journal of Science 1922 
On the north side of Ayoni [Yuni] River near its mouth, fossils were 
found in the limestone which forms the ridge along the western coast of 
the peninsula. 
Fossils collected at locality 44. 
Cypraea sp. Cerithium sp. large internal cast. 
Arca nodosa K. Martin. (?) 
Schizaster sp. 
Along the western coast from Ayoni [Yuni] 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 re- 
lation suggests that the limestone at Ayoni is the Lower limestone, but 
the evidence is not conclusive and either limestone horizon may be repre- 
sented by the fossils from this locality. 
Fossils collected at locality 59. 
Pyrula gigas K. Martin. Pecten leopardus K. Martin. 
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 thickness 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 Nar- 
ciso trail at an elevation of 180 meters, on the east side of the ridge 
extending northwest from Mount Cambagaco. Thin sections of this rock 
show small fragments of limestone and the well-known alga, Lithothamnion 
ramosissimum Reuss, intermingled in a cement of calcite. 
The molluscan fauna of this formation is very sparse when 
compared to that of the Vigo group. This is in part due to poor 
preservation (as the surface waters readily penetrate the cor- 
alline limestones, marls, and sandstones) and in part due to 
original life conditions of deposition. The molluscan fauna 
living on coral reefs in these Islands to-day is not characterized 
by a great variety of forms, and since much of the sediment of 
the Malumbang was laid down as Pliocene coral reefs the mol- 
luscan assemblages found in these coralline limestones or their 
derivative marls consist of relatively few species. 
State of preservation is no guide at all in determining the age 
of faunas 1n the Philippines. Vigo forms are often as well 
preserved as is beach material, while the much younger Ma- 
lumbang fossils are frequently badly decomposed. Even Pleis- 
tocene species secured from raised coralline limestone beaches 
are much older in appearance than Vigo forms. On this account, 
the field man should be especially careful not to permit state of 
