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, Megera, is found in Asia and South Africa. 
