418 bulletin: museum of comparative zoology. 



while in Haiti, for example, three species occur in the very same 

 localities. Since for a very long time there has been and is, especially 

 just at present, considerable controversy regarding the origin of the 

 Antillean fauna, we digress at some length regarding the light which a 

 study of the species throws on the question. 



Bland (Ann. Lye. nat. hist. N. Y., 1862, 7, p. 335) was among the 

 first workers in the field of Antillean zoogeography, studying the 

 relationships of the Mollusca of the different islands. His division 

 of the region into f aunal areas is interesting because his groupings agree 

 well with those of other writers who have based their conclusions on 

 other data. Bland proposed the following areas: — 



1, Cuba and the Isla de Pinos, Bahamas, and Bermudas. 2. 

 Jamaica. 3. Haiti. 4. Puerto Rico and Vieques, the Virgin 

 Islands, Sombrero, Anguilla, St. Martins, St. Bartholomew, and St. 

 Croix. 5. The southern Lesser Antilles, embracing those south of 

 St. Bartholomew to and including Trinidad. 



This grouping of the islands is by no means inconvenient, but it is 

 quite incorrect to conceive that these areas really represent zoogeo- 

 graphic entities, or to say that they are anything more than expres- 

 sions of the close similarity of some species in certain chosen groups. 

 Our thesis is that the West Indian region taken as a whole has a singu- 

 larly compact, homogeneous fauna, the same elements appearing on 

 island after island. This fact is perhaps the most conclusive single 

 argument against the theory of the origin of the fauna by flotation. 

 Several recent writers, among whom may be mentioned Allen (Bull. 

 M. C. Z., 1911, 54, p. 175-263) and Barbour (Bull. M. C. Z., 1910, 52, 

 p. 273-301; and Mem. M. C. Z., 1914, 44, p. 209-347) have been 

 especially active in advocating the interpretation which required a 

 presumed connection of the Antilles with the mainland and with each 

 other to explain the present faunistic conditions. The most able 

 of those who advocate the theory of haphazard population by flotsam 

 and jetsam methods is W. D. Matthew, who has recently summarized 

 his views in a scholarly review entitled Climate and evolution (Ann. 

 N. Y. acad. sci., 1915^ 24, p. 171-318; p. 205, p. 290). In general, 

 the majority of recent naturalists, among them Stejneger, Gadow, and 

 Schaff, are opposed to Matthew's thesis. 



This revision, which is a detailed study of a single genus of strictly 

 terrestrial teid lizards, shows clearly the close relationship and origin 

 from a common stock of many of the Antillean forms. The data 

 derived from this study seem to argue strongly against the flotsam 

 and jetsam theory. Stejneger (Rept. U. S. N. M. for 1902, 1904, 



