DISTKTBUTION OF OnilDTAXS. 241 



(Irophis, the Boa, have hitherto not heen found, except m 

 South America, and the Antilles ; the Tropidonoti, on 

 the contrary, are never found there, but are common in 

 North America, and are also diffused in several of the An- 

 tilles. A small number of species of serpents of South 

 America have also been observed in North America ; these 

 are as follow : Calamaria melanocephala, Lycodon Clelia, 

 Coronella cobella, Herpetodryas cursor, Dryiophis Catesbyi, 

 Elaps corallinus, Homalopsis carinicauda. The Heterodon 

 platyrhinus, and the Herpetodryas sestivus, on the contrary, 

 which are common in North America, have also been dis- 

 covered in Brazil.* The following species inhabit both 

 North America and the Antilles : Calamaria striatula, 

 Coronella coccinea, Heterodon platyrhinus. Coluber con- 

 strictor, Herpetodryas sestivus, and H. cursor, Tropidono- 

 tus bipunctatus, T. fasciatus, and T. saurita. The follow- 

 ing are also found in the Antilles, though their mother 

 country is south America : Calamaria melanocephala, Co- 

 ronella regincie, Lycodon clelia, Dendrophis liocercus, 

 Dryiophis Catesbyi, and D. aurata, Dipsas annulata, Ho- 

 malopsis angulata. Boa constrictor, B. cenchria, and Elaps 

 corallinus. There remain, then, but about four species which 

 are peculiar to the great archipelago of which we speak, 

 namely, Psammophis Antillensis, Trigonocephalus lanceo- 

 latus, Dendrophis Catesbyi, and Boa melanura. In com- 

 paring the serpents of Guyana with those of Brazil, we find 

 that these two countries have a great number of species in 

 common, of which several form local varieties more or less 

 distinct, as is observed in the Herpetodryas lineatus, and 

 H. Olfersii, the Coluber poecilostoma, &c. Several other 

 species appear peculiar to one or other of those countries ; 

 as for example, Calamaria badia, Xenodon typhlus, Coluber 



which the colours are very subject to variation, so that they have been 

 divided into several species, is peculiar to North America. The genera 

 of reptiles peculiar to South America are more numerous ; of those we 

 may cite the Bombinators, the Lizards or Centropyx, the Ceratophrys, 

 the Caecilia, the Amphisbaena, &c. Several of these animals are found 

 also in the Antilles. 



* It may be remarked, that the Heterodon plat3'rhinus and Homa- 

 lopsis carinicauda form local varieties in these two distant places. 



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