11. LACHESIS. 565 
34. Lachesis bilineatus. 
Cophias bilineatus, Wied, Beitr. Nat. Bras. i. p. 483, and Abbild. 
18265). : 
nina teophalis bilineatus, Schleg. Phys. Serp. ii. p. 540, pl. xix. 
figs. 7 & 8 (1837); Peters, Mon. Berl. Ac. 1862, p. 673. 
Craspedocephalus bilineatus, Gray, Cat. p. 7 (1849). 
Bothrops bilineatus, Dum. § Bubr. vii. p. 1514 (1854); Jan, Icon, 
Gén. 47, pl. i. figs. 2 & 3 (1875).. . 
Trigonocephalus (Bothrops) arboreus, Cope, Proc. Amer, Philos. Soc. 
x1. 1869, p. 157. 
Snout rounded, with sharp, somewhat raised canthus. Rostral 
as deep as broad; nasal divided or semidivided; upper head-scales 
small, imbricate, keeled, 5 to 8 in a transverse series between the 
supraocular shields, which aré very large; internasal shields large 
and in contact with each other, followed by a large canthal ; two or 
three postoculars and one or two suboculars, separated from the 
labials by one series of scales; temporal scales keeled; 7 or 8 upper 
labials, second forming the anterior border of the loreal pit. Scales 
strongly keeled, in 27-35 rows. Ventrals 198-218; anal entire; 
subcaudals 59-71, all or greater part in pairs. Tail prehensile. 
Green above, uniform or speckled with black; a yellow lateral 
streak or series of spots running along the outer row of scales; 
belly white ; end of tail reddish. 
Total length 840 millim.; tail 125. 
Brazil, Bolivia, Peru, Ecuador. 
a. & (Se. 29; V. 211; Bahia. Dr. Wucherer [C.]. 
b. (Se. 33; V. 207; Bahia. Zoological Society, 
c. 2 (Sc. 29; V. 193; Campolican, Bolivia. 
d. 2 (Sc. 27; V. 205; Moyobamba, Peru. Mr. A. H. Roff [C.}, 
é. Ye. (Se. 27; V. 201; Canelos, Ecuador. Mr, C. Buckley [C.]. 
f $ ge 27; V. 201; W. Ecuador. Mr. Fraser [C.]. 
35. Lachesis undulatus. 
Trigonocephalus (Atropos) undulatus, Jan, Rev. §& Mag. Zool. 1859, 
p- 157, and Prodr. pl. E (1859). 
Atropos undulatus, Jan, Elenco, p. 127 (1863). 
Teleuraspis undulatus, Garm, N. Am. Rept. p. 126 (1883). 
Guerre undulatus, Cope, Bull. U.S, Nat. Mus. no. 32, 1887, 
a. 
Bothrops undulatus, Giinth, Biol. C-Am., Rept. p. 187 (1895). 
Snout short, rounded, with well-marked canthus. Rostral once ° 
and a half to twice as broad as deep; nasal divided; upper head- 
scales very small, juxtaposed or subimbricate, 14 to 20 across from 
eye to eye; no supraocular shield, but a long erect horn-like scute 
above the eye; internasals small ; some of the scales on the canthus 
