20, 3 Schenck: Physiography and Geology of Samar 265 
of the latter one can recognize, according to Dr. von Martens, among the 
numerous shell fragments, Plicatula depressa Lamarck, which is still living 
in the Indian Ocean. The yellowish gray clay banks under these horizontal 
layers dip inland. According to Dr. von Martens, from among the fairly 
well-preserved shells and pteropods, one can identify, in part, the following 
species [genera]: Yoldia, Pleurotoma, Cuvieria, Creseis, Dentalium, which 
still live in the Indian Ocean. The species Pleurotoma is not identified 
with any one living species. With the living species can be recognized 
the following: Venus (Hemitapes) hiatina Lam., Venus squamosa L., 
Arca (Scapharea) cecillei Phil., Arca inaequivalvis Brug. var." Arca chel- 
canthum Rv.?, Corbula crassa Rv., and Natica unifasciata Lam. var. lurida 
Phil. 
In the forest between Paranas and Loquilocan which stretches to the 
northeast and toward the land are cliffs of solid, grayish white limestone, 
resembling conglomerate, interwoven with veins of calcareous spar (calcite) 
and in which may be recognized indistinct organic remains, perhaps of 
corals. In the Loquilocun River, which directs its course toward the 
northeast to the east coast of the island, there are, below the Loquilocun 
chapel, brownish yellow, badly weathered calcareous sediments in great 
unstratified masses. The coal which forms an alluvial deposit near the 
sixth rapids below Loquilocun is rich in pyrites and interwoven with gypsum, 
and is similar to the wood of lignite. Its woody structure can be seen 
with the naked eye and it gives a brown powder. 
From a large alluvial deposit of gravel and rubble opposite the rapids 
below Loquilocun, where the boat must be unloaded for the first time and 
the cargo carried overland, can be obtained the following: (1) A much- 
altered, granular, red-gray rock veined with epidote; in it can be seen, 
besides quartz and triclinic feldspar, a fair number of points of magne- 
tite; it does not impress one as an eruptive rock and could belong to the 
feldspar series of hornblende-schists; (2) a blue-gray, porphyritic rock 
whose vitreous groundmass (lacking the property of double refraction) is 
filled with small sphalerites and contains sparingly small grains of 
quartz and magnetite, besides larger dull white feldspars. Only on one 
of the crystals could the triclinic bands be recognized with certainty. 
The rock is probably a recent eruptive but a further classification is 
doubtful; at any rate, the presence of quartz in the vitreous groundmass 
is of interest. The grains of quartz cannot be considered as incrustations; 
(8) farther on is an agate of milky white color, one of the amygdaloids, 
as the surface proves; (4) red-brown jasper interwoven with fine quartz 
veins. 
Bowlders from Basey River (southern coast of the island) accumulated 
at the Sogoton cave, are composed of an old eruptive rock. It contains 
in a fine-grained dark green groundmass dull white feldspar, a little 
magnetite, and some indeterminate greenish crystals, which may be con- 
sidered to be augite. Conforming to this composition and the behavior of 
the rock and the feldspars with boiling hydrochloric acid, the rock belongs 
to an oligoclase-augite-porphyry. The red-brown, ferruginous soft rock 
which occurs near the preceding one and which effervesces in acids and 
“The teeth are somewhat more numerous and smaller than in A. aequt- 
valvis Brug. Jagor, Philippinen. 
