Ch. X.] 
EAST INDIAN ARCHIPELAGO. 
133 
western range consists in great part of formations of the most 
modern period. It will be remembered, that many parts of 
this region have been subject to violent earthquakes; that in 
St. Vincent's and Guadaloupe there are active volcanos, and 
in some of the other islands boiling springs and solfataras. In 
St. Eustatia, there is a marine deposit, estimated at 1500 feet 
in thickness, consisting of coral limestone alternating with beds 
of shells, of which the species are, according to Maclure, the 
same as those now found in the sea. These strata dip to the 
south-west at an angle of about 45°, and both rest upon, and are 
covered by, cinders, pumice, and volcanic substances. Part of 
the madreporic rock has been converted into silex and calced- 
ony, and is, in some parts, associated with crystalline gypsum. 
Alternations of coralline formations with prismatic lava and dif- 
ferent volcanic substances also occur in Dominica and St. 
Christopher's, and the American naturalist remarks, that as 
every lava-current which runs into the sea in this archipelago 
is liable to be covered with corals and shells, and these again 
with lava, we may suppose an indefinite repetition of such 
alternations to constitute the foundation of each isle. 
We do not question the accuracy of the opinion, that the 
fossil shells and corals of these formations are of recent species, 
for there are specimens of limestone in the Museum of the 
Jardin du Roi at Paris, from the Antilles, in which the im- 
bedded shells are all or nearly all identical with those now 
living. Part of this limestone is soft, but some of the 
specimens are very compact and crystalline, and contain only 
the casts of shells. Of 30 species examined by M. Deshayes 
from this rock 28 were decidedly recent. 
Honduras. — Shells sent from some of the recent strata of 
Jamaica, and many from the nearest adjoining continent of 
the Honduras, may be seen in the British Museum, and are 
identified with species now living in the West Indian seas. 
East Indian Archipelago. — We have seen that the Indian 
ocean is one of the principal theatres of volcanic disturbance. 
We expect, therefore, that future researches in this quarter of 
