24 BROOKLYN BOTANIC GARDEN MEMOIRS 
cluding its islets, of about 21 square miles. The total area of the 
three islands, including their contiguous islets, is thus about 1 38 
square miles, or not quite twice that of Staten Island. The areas 
here used for St. Thomas and St. Jan are approximate, because the 
total area of the contiguous islets is not definitely recorded. 
The harbor of Charlotte Amalia, coveted by commercial and naval 
interests, is the most striking coastal feature of the islands, indenting 
the southern coast of St. Thomas. It is something less than a mile 
in diameter, a little longer than wide, and is nearly enclosed by the 
hills, its mouth being approximately 900 feet wide. It is as safe an 
anchorage as any tropical harbor can be, and affords anchorage for as 
many vessels as would be at all likely to need it at any one time, in 
water which is up to 37 feet deep. It is not as spacious as Guantanamo 
Bay on the southeast coast of Cuba, but as a naval base, with the 
hills fortified, would immediately command the Virgin Passage. 
Magen’s Bay on the north side of St. Thomas, where a long penin- 
sula juts out into the sea, and Coral Bay at the east and Cruz Bay 
at the west end of St. Jan, are also valuable harbors, and there are 
several other small harbors or coves. The so-called harbors at 
Christiansted and Frederiksted, St. Croix, are open roadsteads. 
These islands, like Culebra, Tortola, and Virgin Gorda, are partly 
plutonic in origin, being partly composed of rocks which have solidified 
froma molten state. There is no present evidence of volcanic activity, | 
as there is in the Leeward and the Windward Islands farther south, 
and there are no volcanic peaks. Conglomerate and other stratified 
rocks, supposed to be Cretaceous, also occur. They are evidently 
ancient, and show evidences of an enormous amount of erosion since 
their upheaval; they have not been geologically surveyed. 
The soil, except that of some sand beaches and mangrove swamps 
and salt marshes, has directly resulted from the decay and erosion 
of the rocks; it is of good agricultural quality and locally deep, but 
on the steep slopes and hillsides it is meager, having been much 
washed away since the cutting away of the forests. There are not 
many sand beaches on St. Thomas or St. Jan, but there is a consider- 
able area of beach on St. Croix. In sheltered coves and reaches with 
shallow water, the mangrove is forming land, as everywhere in similar 
situations on tropical coasts. 
Along large portions of the coast lines, the rocks come directly 
to the sea, forming fine cliffs and headlands, often rising from deep 
water, and much of the coastal scenery is highly picturesque. 
I have included records of the plants commonly cultivated either 
for their products or for ornament and interest, but have made no 
attempt to include the rarer or unusual garden plants. If the records 
