AMERICAN AND WEST INDIAN FAUNA AND FLORA. Ill 



of things existing along the Lesser and Greater Antilles in a 

 former period, we are at once struck by the fact that the Virgin 

 Islands are the outcropping of an extensive bank. The great- 

 est depth between these islands is less than forty fathoms, a 

 depth which is found on the bank to the east of Porto Rico, — 

 the hundred-fathom line forming, in fact, the outline of a large 

 island, which would include the whole of the Virgin Islands, 

 the whole of Porto Rico, and extend some way into the Mona 

 Passage. The hundred^fathom line similarly forms a large 

 plateau, uniting Auguilla, St. Martin, and St. Barthelemy. It 

 also unites, as separate banks, Barbuda and Antigua, forms the 

 Saba Bank, and unites St. Eustatius, St. Christopher, and Nevis. 

 It unites Redonda with Montserrat. It forms an elongated 

 plateau, from Bequia to the southwest of Grenada, and runs 

 more or less parallel to the South American coast from Mar- 

 garita Island, leaving a comparatively narrow channel between 

 it and the hundred-fathom line south of Grenada, so as to 

 enclose Trinidad and Tobago within its limits, and runs off to 

 the southeast in a direction also about parallel to the shore 

 line. At the western end of the Caribbean Sea the hundred- 

 fathom line forms a gigantic bank oif the Mosquito coast, 

 extending over one third the distance from the mainland to 

 the island of Jamaica. The Rosalind, Pedro, and a few other 

 smaller banks, limited by the same line, denote the position of 

 more or less important islands which may have once existed 

 between the Mosquito coast and Jamaica. On examining the 

 five-hundi'ed-fathom line, we thus find that Jamaica is only the 

 northern spit of a gigantic promontory, which perhaps once 

 stretched toward Hayti from the mainland, reaching from Costa 

 Rica to the northern part of the Mosquito coast. There is left 

 but a comparatively narrow passage between this promontory 

 and the five-hundred-fathom line which encircles Hayti, Porto 

 Rico, and the Virgin Islands, in one gigantic island. 



The passage between Cuba and Jamaica has a depth of over 

 three thousand fathoms, and that between Hayti and Cuba is 

 not less than eight hundred and seventy-three fathoms in depth. 

 The five - hundred - fathom line connects the bank unitino- 

 Anguilla to St. Barthelemy, the Saba Bank, the one which joins 



