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and the southernmost part of Flori(hi. Thus the West Indian colony 

 of insects in Florida may come from any part of this vast area swept by 

 the Gulf stream, although the largest proportion comes of course from 

 Cuba since this island is the nearest to Florida. This immigration by 

 the aid of the Gulf stream explains the following interesting phenomenon 

 in geographical distribution. We have seen that insects from the coast 

 of Central America south of Yucatan may occur in Southern Florida ; 

 but the same species often had the power of extending their geographi- 

 cal distribution northward on the Central American mamland through 

 Mexico, thus reaching the south-western limits of the United States. 

 Certain species may occur, therefore, in the United States, in Western 

 Texas or South-eastern New Mexico and in Southern Florida, being 

 however, absent in the intervenmg Southern States, viz : Eastern Texas, 

 Louisiana. Alabama, Georgia, and Northern and Central Florida. This 

 curious distribution has never been pointed out so far as I am aw-are 

 but can be exemplified by numerous species, not only among the Co- 

 leoptera but also other Orders of insects. 



The distance between Cuba and Florida is not very great, the current 

 of the Gulf stream is very swift, and logs and other debris swept out to 

 sea from the rivers of Cuba may reach the coast of Florida within three 

 or four days ; from Yucatan in about double that time. It is evident 

 that within this short time all such insects may safely be carried from the 

 West Indies to Florida which, in the imago or praeparatory stages, live 

 under bark, or within the wood of trees, or within seeds and similar 

 slieltered conditions, or whose eggs are firmly attached to trees and cover- 

 ed with viscous liquid. But it is evident that this sea voyage is too long 

 for all such insects as do not live in such sheltered positions. As a con- 

 sequence, all adephagous Coleoptera, further all those living under old 

 leaves, in the ground, in very rotten wood and similar places, and finally 

 most of the CbrysomelidcB which lay their eggs either on to the leaves or 

 in the ground are not brought over from the West Indies. There are, 

 therefore, no West Indian Carabidce, Lampyrida, Staphylinidce and other 

 rhypophagous Clavicorn families and very few^ West Indian ScarabccidcB 

 and Chiysomelidir to be found in Southern Florida.* This is a most 

 characteristic feature of the semitropical Coleopterous fauna of Florida, 

 strikingly contrasting with the state of affairs in the south-western ex- 

 tremity of North America. I have stated before that along the Texan 

 and New Mexican frontier there is a perfect intermingling of the North 



* The absence of fresh water in the coral region of the Keys and tlie mainland 

 south of Miami River necessitates the absence of Dytiscidie and most other aquatic or 

 semi-aquatic families. Even the Everglades and the rivers draining the same at the 

 northern end of Biscayne Bay seem to be almost destitute of acquatic Coleoptera. 



