126 
FOURTEENTH REPORT. 
No evidence lias been detected that the movements of the islands have 
been independent of those of the neighboring coast, on the contrary 
they appear to have shared those of the mainland throughout. The later 
of these movements have been fully correlated by high authority with 
the Glacial elevation and Champlain depression of the East. 
NICARAGUA. 
In Nicaragua, Belt* found evidence that the glaciers came down from 
the mountains to the present 2,000 foot level. He speaks of unstratified 
drift with transported boulders as large as fifteen feet across and eight 
miles from their parent rock. He is not sure that the glaciers did not 
come down even lower than the level named. 
In the matter of the life of the region, he reasoned that it must have 
survived the cold spell without migrating any great distance, that there 
must have been fairly extensive lowlands near by in order for it to sur- 
vive. that this period of cold was apparently identical with the period 
of a land connection between Yucatan and the Greater Antilles and 
from other data also he believed that during the Glacial period Nicar- 
agua stood much higher relative to the sea than it does now. He at- 
tributed this to the ocean being lowered by the abstraction of water 
which was stored up in the form of glaciers elsewhere. 
THE WEST INDIAN REGION. 
Bland, f studying the land mollusca of the Antilles found the fauna 
of Cuba and the remainder of the east-and-west component, the Greater 
Antilles, to be derived from Mexico and Central America; that of the 
north-and-south component, the Lesser Antilles, to be derived from 
South America by the way of Trinidad. 
Simpsont emphasizes the “rather intimate” relationship of the Greater 
Antilles with Central America and Mexico and the much more remote 
one with the Lesser Antilles. 
Ortinann,§ mainly on the basis of the freshwater Crustacea, believes 
in a pleistocene connection between the Greater Antilles and Central 
America which was destroyed in recent time, lie holds similar views 
in regard to the connection of the Lesser Antilles, Trinidad and the 
South American mainland, citing Simpson as favoring the drift theory 
for tlx* shells but. himself, believing that the decapods demand a land 
bridge. 
Pilsbryjl concurs on this connection, and in view of the weight of 
opinion in its favor it becomes interesting to learn what depths of water 
now separate these islands, since these depths may be regarded as approxi- 
mated thi* measure of the vertical movement that has converted them from 
a fairly continuous ridge into the present chain of islands. We find on 
*RHf Thomas, “The Naturalist in Nicaragua.” London, 1874. 
fBland, Thomas, “Notes relating to the Physical Geography and Geology of and the Distribution 
of Terrestrial Mollusca in certain of the West India Islands.” Proc. Am. Philos. Soc., vol. xii, 1871, 
' ' tSimpson. Charles Torrey, “Distribution of the Land and Freshwater Molluscs of the West Indian 
Region, and their Evidence with Regard to Past Changes of Land and Sea.” Proc. U. S. Nat. Mus. 
vol xvii, 1894, pp. 423-450. 
SOrtmann. A. E., “The Geographical Distribution of Freshwater Decapods and its bearing upon 
Ancient Geography.” Proc. Am. Phil. Soc., vol. xli, 1902, No. 171, pp. 267-400. 
llPilsbry. H. A.‘ "Non-Marine Mollusca of Patagonia.” Reports, Princeton Univ. Expeditions to 
Patagonia, 1896-1899, vol. iii. 
