For Zoographers Only 303 



vastly smaller tlian was once supposed when it was thought 

 that reptiles, amphibians, land mollusks, and in fact almost 

 all orders of animals were carried hither and thither 

 throughout the oceanic areas. 



Mr. Agassiz has expressed an opinion on this series of 

 relationships in his chapters in The Three Cruises of the 

 Blake entitled "American and West Indian Fauna and Flora" 

 and "Permanence of Continents and Oceanic Basins." The 

 following (loc. cit.y 14, p. m) is pertinent: — 



At the western end of t':e Caribbean Sea the 

 hundred-fathom line forms a gigantic bank off 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 be- 

 tween the Mosquito coast and Jamaica. On examining 

 the five-hundred-fathom line, we thus find that Ja- 

 maica is only the northern spit of a gigantic promon- 

 tory, which perhaps once stretched toward Hayti from 

 the mainland, reaching from Costa Rica to the north- 

 ern part of the Mosquito coast. There is left but a 

 comparatively narrow passage between this promon- 

 tory 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. 



