SNAKES. 21 



This family consists of 11 genera and 37 species: 31 of the 

 species are contained in the Museum collection. Schlegel, in his 

 last work on the species of snakes, described 17 species. The genera 

 1, Craspedocephalus ; 6, Lachesis ; 7, Trigonocephalus ; 8, Cenchris ; 

 9, Crotalophorus ; 10, Uropsophus, and 11, Crotalus, are confined to 

 America: 2, Trimesurus ; 3, Parias, and 5, Atropos^ to Asia and 

 its Islands: 4, Megcera, is found in Asia and South Africa. 



