1	Tail tip with distinguished structures	2
–	Tail tip undistinguished; postocular stripe present	3
2	Tail with rattle; brown arrow shaped dorsal scales with white bordered and dark center diamond shape	Crotalus durissus cascavela
–	Tail tip with spiked scales; orange coloration with dark diamond blotches along the body; postocular stripe present	Lachesis muta rhombeata
3	Dorsal scales with 19 or 21 rows; Pale brown coloration, reddish blotches half-moon shaped with circular spots on margin; fewer than 158 subcaudals	Bothrops erythromelas
–	Dorsal scales with 21 or more rows	4
4	Dorsal coloration varies from grayish to dark brown; Dark dorsal blotches bow shaped bordered by 1–2 white scales and separated by circular blotches; venter cream and pigmented; Immaculate supralabials. 172–212 ventrals	Bothrops leucurus
–	Ground color grayish with elongated dark blotches half-moon shaped; Occasional white spots on supralabials; 153–156 ventrals for three specimens from north of Salvador (elsewhere 161–179, Campbell and Lamar 2004)	Bothrops lutzi