DISTEIBUTION OF OPHIDIAISTS. 
241 
drophis, the Boa, have hitherto not been found, except in 
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 reginae, 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 
whicli 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 Ceecilia, the Amphisbsena, &c. Several of these animals are found 
also in the Antilles. 
* It may be remarked, that the Heterodon platyrhinus and Homa- 
lopsis carinicauda form local varieties in these two distant places. 
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