HILL: GEOLOGY OF JAMAICA, 15 
extensive, thorough, and painstaking studios of the fossil corals, includ- 
ing not only careful examination of all the material in hand, but also 
personal visits to nearly all the European Museums where the collections 
of previous workers are preserved. His determinations have been the 
chief reliance in the interpretation of many obscure points. His studies 
will be published elsewhere more in extenso. 
PART I. 
Geography and Physiography. 
The island of Jamaica is situated between North Latitude 17° 40’ and 
18° 3’ and West Longitude 75° 10’ and 78° 23’. Its northern shore lies 
almost due south of the western half of the Sierra Maestra coast line of 
Cuba, from which it is 65 miles (nautical) distant. Between these 
islands lies the eastward prolongation of the great Bartlett depression, 
3,000 fathoms deep. The eastern coast is about the same distance from 
Cape Tiburon, the western point of the island of Haiti, and is separated 
therefrom by 1,000 fathoms of water. On the south lies a wide stretch 
of the Caribbean, 2,000 fathoms deep. Cape Gracias á Dios, the nearest 
Central American land on the western coast of Honduras, is 780 nautical 
miles distant. Between the Isthmian-Honduran continental littoral and 
Jamaica extends the Rosalind and Pedro Banks, less than 500 fathoms 
deep, which constitute an extensive shallow submarine platform, indented 
at one place by a narrow submarine strait of less than 1,000 fathoms. 
Jamaica is almost the exact centre of the great American Mediter- 
ranean. By drawing straight lines through the island, as shown in 
Figure 5, from Galveston to the mouth of the Orinoco, from the southern 
point of Florida to the northern part of South America, from the eastern 
end of the Antilles (St. Thomas) to the western indentations of the 
Gulf of Honduras, and from the most northern Bahama to the Gulf of 
Atrato, the central position of the island will be apparent, for it will be 
found at the point of intersection of these radiating lines and about equi- 
distant from their termini. This central position of the island is im- 
portant from geographic, biologic, and geologic points of view, and makes 
it a typical base of study for one interested in Antillean problems. 
Like a measuring gauge set up in the middle of a stream to record the 
riso and fall of a river, it stands in the centre of the American Mediter- 
ranean, —a standard geological index of the great oscillatory changes 
of level which have taken place in the history of Tropical America, whose 
