INTRODUCTION. 213 



species were already well represented and only such species as were especially 

 desirable were searched for. 



The revival of interest in zoogeography has prompted making this paper 

 more than a simple check Hst, although such a list of the reptiles and amphibians 

 of the Antilles has long been needed. The species which are included in this 

 list are only those which seem to be worthy of recognition; all other recorded 

 species are considered synonyms or incorrect records for the area. This com- 

 prises the Bahamas, Greater and Lesser Antilles as far south as Grenada; Swan 

 Islands and the Cayman group are also included. As stated elsewhere among 

 the notes on certain species, the practice has been followed of recognizing island 

 races as far as possible. It is considered that a more incorrect concept is gained 

 regarding the conditions among these islands by stating that the same species 

 occurs upon several islands, when there is generally a constant definitive varia- 

 tion seen in individuals from each island, even though in some cases this varia- 

 tion appears to be shght. Jordan's law of evolution by isolation has often been 

 startlingly effective in producing very distinct species upon nearly adjacent 

 islands, where these islands have apparently — indeed, one might say certainly — 

 exactly the same physical and cUmatic conditions. 



No attempt is made to give complete synonymies; and unless some special 

 comment is made, those species which have been considered synonyms by 

 Boulenger in his catalogues are so accepted. 



This paper must be considered in the nature of a preliminary, since unfortu- 

 nately press of time and in many cases want of material have prevented the writ- 

 ing of a herpetology, with descriptions and keys for the identification of species. 

 This list will show where reptile collecting in the West Indies can be carried on 

 most profitably, what material from the region is a\'ailable for study in the 

 Museum of Comparative Zoology; and these records, which have been carefully 

 culled, serve as a basis for certain considerations regarding the geographical dis- 

 tribution of Antillean reptiles and amphibians, and regarding the origin of this 

 fauna. 



Note. — After this paper was about completed, Mr. George Nelson of the 

 Museum staff made three visits to the Swan Islands thanks to the kindness of 

 Dr. W. A. Brooks. Together several months were spent there, and collections 

 made in winter, spring, and smnmer. For the first time the islands have been 

 studied by the same person at various times of the year. Mr. Nelson's material 

 force the reconsideration of conclusions which maintain that the Swan Islands 

 had an oceanic origin. Special mention may be made of the very strange fact 



