11. LA0HESI8. 543 



9. Lachesis ammodytoides. 



Bothrops ammodytoides, Leybold, Escurs. Pamp. Argent, p. 80 (1873) ; 



Berg, An. Soc. Arg. (5) xix. 1885, p. 236 ; F. Mull. Verh. Nat. 



Ges. Basel, viii. 1887, p. 284. 

 EWnocerophis nasus, Garm. Bull. Mtts. Comp. Zool. viii. 1881, p. 85. 

 Bottrops nasus, Berg, Act. Ac. Cordoba, v. 1884, p. 96. 

 patagonicus, J^. Mull. Verh. Nat. Ges. Basel, y\i. 1885, p. 697. 



Snout turned up and produced in a low wart, as in Vipera latastii. 

 IBostral once and a half as deep as broad ; nasal divided ; upper 

 head-scales small, imbricate, keeled ; supraocular large, separated 

 from its fellow by 8 or 9 series of scales ; two series of scales 

 between the eye and the labials ; temporal scales keeled ; 9 or 10 

 upper labials, second separated from the loreal pit, third and fourth 

 largest. Scales very strongly keeled, in 23 or 25 rows. Ventrals 

 149-1 60 ; anal entire ; subcaudals 30-38 pairs. Pale brown above, 

 with large square dark brown black-edged spots or cross-bands 

 which may alternate and form a zigzag band ; a dark streak behind 

 the eye ; belly yellowish, dotted with brown. 



Total length 460 millim. ; tail 65. 



North-eastern Patagonia and. Argentina. 



.a. S (Sc. 23 ; V. 156 ; C. 37). Rio de Cordoba, E. Fielding, Esq. [P.]. 



Argentina. 

 .i. 2 (Sc. 23 ; V. 149 ; C. ?). ? Haslar OoUection. 



10. Lachesis xanthogrammus. 



Trigonocephalus xanthogrammus. Cope, Proc. Ac. PMlad. 1868, 



p. 110. 

 ? Bothrops quadriscutatus, Posada- Arango, Bull. Soc. Zool. France, 



1889, p. 345. 



Head elongate ; snout short. Rostral deep ; nasal divided ; 

 upper head-scales aU smooth, in 9 or 10 longitudinal series between 

 the large supraoculars ; four elongate shields in a row on the end 

 of the snout ; 7 upper labials, second forming the anterior border 

 of the loreal pit. Scales not strongly keeled, in 27 rows. Ventrals 

 196 ; subcaudals 54. Very dark olive above, with a yellow zigzag 

 line on each side from the head to the base of the tail, the apices of 

 the open A's usually meeting on the vertebral line, enclosing dorsal 

 rhombic spaces and lateral triangles ; top of head black, with a pair 

 of undulating yellow bands from the nape meeting in a A on the 

 vertex ; a bright golden band round the end of the snout, involving 

 the greater part of the supraocular shields, and extending to the 

 nape, bounded below by a black band from the eye to the angle of 

 the mouth ; labials bright yellow ; ventral shields black, paler in 

 the middle, with yellow triangular spots at their extremities. 



Total length 1530 millim. ; taU 190. 



PaUatanga, E. Ecuador ; Andes of Colombia (?). 



