CLASS REPTILIA. 



Order Ophidii. Serpents.^ 

 The jaws very dilatile; the mastoid bones free from the 

 skull, and the branches of the lower jaws free in front ; 

 legs o, body with a row of larger scales benenth. 



I. Upper jaw toothless, fangs large, distinct vertebral 

 plates broad ; tail short, conical. Venemous. 



Gen. 1. Crotalus. Rattle-snakes. 

 Head broadly triangular, with a large pit before the eyes. 



A. Tail with a rattle, head covered with scales like the back. 



Crotalus. New World. 



Common Rattle Snake. Crotalus Horridus, Lin. Cates- 



by, ij. t. 41. Crot. Catesbaei. Hempr. Lozenge spotted 



Rattle-snake. Crotalus Durissus. Cr. Horridus. Pr. Max. 



Ch. Rhombifer, Boie. Cr. Cascavella, Spix, t. 24. add 



Cr. Confluentus, as North America, and Boie has indicated, 

 in the Leyden Mus. C. Atricaudatus, and C. Drijinus ; 

 and Humboldt in his Zoological observation describes Cro- 

 talus Loeflingii. Crot. Strepitans, Daud. Seba, ij. t. 96. 

 f. 2, is said to be Boa Canina ; and Crot. triseriatus, Weig- 

 mann. Is referred to Mexico. 



B. Tail with a rattle, head with shields. Crotalophorus, 



Gray. Caudisona, Fitz. 



Miliar Rattle-snake. Crotalophorus Miliaris. Crotalus, Lin. 

 Catesby, ij. t. 42. Mus Brit. See also Crot. Tergeminus, 

 Say. North America. 



* It has been found absolutely necessary to omit the specific characters 

 of the ensuing divisions of this class. Ed. 



The Catalogue on the Species, is greatly dependant on the one pub- 

 lished by Boie, in the Iris, Vol. xx. The species are separated by a short 



dash, thus . J. E. G. 



78 



