APTENDIX A. 



AN ENUMERATION OF THE GENERA AND SPECIES OP RATTLESNAKES, 

 WITH SYNONYMY AND REFERENCES. 



By E. D. COFE. 



That large assemblage of serpents, known as the Viperidce of Bonaparte, Viperina 

 of Gray, or Solenoglyphes of Dumeril, exhibits the most perfect degree of develop- 

 ment of those points of structure which distinguish all venomous serpents from 

 those that are innocuous. Of the subgroups of genera and species contained in this 

 ''familj'," or "suborder," none is more truly representative than that denominated 

 by the authors just mentioned, Crotalina, Crotalida;, and Crotalicns respectively, 

 and which is characterized by the possession of a deep pit in the maxillary region, 

 in front and below the level of the eye. Preeminent among the Crotalina for size, 

 strength, and power of inflicting injury, are those species in which the tail termi- 

 nates in a jointed corneous appendage, termed the rattle, from which their name 

 of Rattlesnakes is derived. These serpents exhibit two types of form, which are 

 distinguished by the following characters : — 



Anterior part of the top of the head covered by small scales. Caudisona. 



Anterior part of the top of the head covered by nine plates, symmetrically arranged. Crotalus. 



In the following pages will be given an enumeration of the species of these two 

 genera, under their correct names, with a description of the Caudisona horrida, 

 the species which has been the subject of Dr. Mitchell's experiments. 



II. 

 CAUDISONA Laurenti. 



ITGS. Caudisona : Laurenti, Specimen Synopsis Rcptilium, p. 92. 



1789. Crotalus : LACEptoE, Histoire Naturelle des Serpens, II, 130. Nee Linna^i. 



1802. " Daudin, Histoire Natnrclle des Reptiles, V, 29'7. 



1817. " CuviER, Regno Animal, II, 77. 



1830. " Wagler, Naturlieh. Syst. der Amphibicn, p. 17G. 



1837. " ScuLEGEL, Essai sur le Physionomie des Serpens, II, 555. 



1842. " Gray, Zoological Miscellany, p. 51. 



1843. " FiTZiNGER, Systema Reptilium, p. 29. 

 1849. " Gray, Catal. Brit. Museum, p. 19. 



1853. " Baird et Girard, Catal. Serp. Smiths. Inst., p. 1. 



