BUSH MASTER (Lachesis nautus), one of the largest mem bers of the rattlesnake family, reaching a length of 8ft. It in habits the Amazon region and is extremely venomous, with very large fangs. The tail terminates in a spine which makes a rustling sound as the snake moves. The bush master and the diamond back rattlesnake of the southern United States are the largest American poisonous snakes.
See C. Darwin, Voyage of the Beagle (1845) ; H. W. Bates, A Naturalist on the River Amazons (1884) ; E. G. Boulenger, Reptiles and Batrachians (1914) .