For Zoographers Only 305 



were included the Bahamas, Florida, Cuba, San 

 Domingo, Porto Rico, and the Virgin Islands. 



If we grant for the sake of argument that the Greater 

 Antilles, like all Oceanic Islands, have received their fauna 

 fortuitously, we must then explain the regularity and con- 

 sistency with which the fauna has spread from two direc- 

 tions to populate such a great number of separate islands, 

 with and against the prevaihng wind and current. We find 

 in the Lesser Antilles that the fauna is of almost purely 

 northwest South American origin; as we pass thence to 

 St. Thomas and to Porto Rico we note, as Stejneger has 

 shown, the very evident twofold origin already mentioned. 

 Then in Jamaica and Cuba the balance is in the opposite 

 direction — types of Central American origin predomi- 

 nate. 



The ancestry of Cricosaura, Amphisbaena, Bufo, and 

 many other forms recently discovered prove that migra- 

 tion to these two islands took place along independent 

 land bridges. The Jamaican coney belongs to a different 

 section of the genus (Capromys), similar to the Haitian 

 and different from the Cuban species, and Solenodon occurs 

 in Cuba and Haiti and not now — nor, so far as we know, 

 did it ever — in Jamaica; these facts prove or help to prove 

 the independent connection with Haiti of both Cuba and 

 Jamaica. Finally, in favor of the "bridge theory" Dr. Stej- 

 neger in a recent letter writes: "Whatever the mountain 

 structure may show, certainly the geographical distribu- 

 tion of the animals shows that the Greater Antilles have 

 been part of a continent at some time." 



That Dr. Stejneger's opinion represents views which are 



