288 ORIGIN OF LIFE IN AMERICA 



Dr. Stejneger,* a few Antillean. genera, suah as Ameiva, 

 Amphisbaena, Typhlops and Alsophis, possess aisouthern rela- 

 tionship. The species of burrowing snake, Typhlops lumbri- 

 calis, is even confined to the West Indies and British Guiana 

 without entering Central America. Dr. Stejneger does not 

 actually speak of a former land connection of Antillea with 

 South America, but I explained above that some geologists 

 advocate an ancient union of the two continents by way of 

 the Lesser Antilles. If such a connection existed, I think 

 it must have been in the pre-Cretaceous times. Most zoo- 

 logists would deride the idea of any terrestrial species 

 having been transmitted to us unchanged from pre- Cretaceous 

 times to the present day. We have no geological evidence of 

 such a faot, but Dr. Sarasin expresses the opinion that the 

 genus Typhlops, at any rate, is older than the Cretaceous 

 Period. We gather from Dr. Stejneger's researches that the 

 great majority of the Portorican species are western in their 

 affinities, and that Portorico and the more easterly Virgin 

 islands certainly must have been connected with one another 

 in comparatively reoent geological times. 



As regards Jamaica, Mr. Barbour gives us some interesting 

 details as to its reptiles and amphibians. He emphasises the 

 fact, which I have already alluded to in speaking of the 

 mammals (p. 285), that the distinctive characters of this 

 island are not shared by the rest of the Antilles. Jamaica is 

 related faunistically to Central America and' Haiti, while the 

 relationship with Cuba is much more remote. Mr. Barbour 

 thinks that the early separation of Jamaica from the main- 

 land and from Haiti would account for the absence of types 

 having such a distribution as Bufo and Amphisbaena, which 

 may have reached Haiti from Central America by way of 

 Cuba. If fortuitous dispersal has played practically no part in 

 providing the Antilles with a fauna, as Mr. Barbourf is in- 

 clined to think, the Bahamas certainly must have belonged to 

 Antillea and cannot have been submerged since. Sixteen 

 species of reptiles and amphibians are described by Mr. 

 Barbourf as occurring in the Bahaman archipelago. Several 



* Stejneger, L., " Herpetology of Porto Eico," pp. 561 — 563. 

 t Barbour, Thomas, " Herpetology of Jamaica." pp. 271 — 285. 

 X Barbour, Thomas, "Batrachia and Eeptilia of Bahamas." 



