11. LAcHEsIs. 541 
a. Hgr. (Sc. 23; V. 157; C. 45). Lima. Christiania Mus. 
6, ¢. Ve. (Sc. 22; V. 167; C. 42) Lima. Prof. W. Nation [P.]. 
& head and tail (OC. 40) of 9. 
7. Lachesis alternatus. 
Craspedocephalus brasiliensis (non Lacép.), Gray, Cat. p. 5 (1849). 
Bothrops alternatus, Dum. § Bibr. vii. p. 1512, pl. Ixxxii. fig. 1 
1854) ; Guichen. in Casteln. Anim. Nouv. Amér. Sud, Rept. p. 76 
885) Jan, Icon. Gén. 47, pl. vi. fig. 1 (1875) ; Bouleng. Ann- 
Mag. N. H. (5) xviii. 1886, p. 488. 
Trigonocephalus alternatus, Jan, Rev. § Mag. Zool. 1859, p. 155. 
Bothrops atrox, part., Hensel, Arch. f. Nat. 1868, p. 334..,, 
Head narrow, elongate; snout obtusely pointed, with sharp: 
canthus. Rostral as deep as broad or a little deeper than broad ; 
nasal divided ; upper head-scales small, imbricate, strongly keeled, 
in 10 to 13 longitudinal series between the supraoculars, which are 
rather narrow; a pair of large internasals, in contact with each 
other, each followed by a canthal; two or three postoculars and 
one or two suboculars, separated from the labials by two series of 
scales; loreal pit separated from the labials by small scales ; temporal 
scales keeled; 8 or 9 upper labials, second small. Scales very 
strongly keeled, in 29-35 rows. Ventrals 167-181; anal entire ; 
subcaudals 34-51 pairs. Brown above, very elegantly marked with 
opposite or alternating pairs of large C-shaped, dark brown markings 
edged with black and yellow and separated by narrow interspaces 
of the ground-colour; a series of smaller spots on each side; head 
dark brown above, with a J-shaped light marking, the transverse 
branch between the eyes, and a light line from the canthus rostralis 
to the angle of the mouth; rostral and anterior labials white, the 
former with a dark brown vertical bar; chin and throat with dark 
longitudinal streaks; belly whitish, spotted with brown or black 
tail with two dark streaks below. 
Total length 1190 millim. ; tail 110. 
Southern Brazil, Paraguay, Uruguay, Argentina. 
a,b. 2 (Sc. 29,32; V.188, Brazil. 
178; C. 34, 32). 
ce, d-e. g (Sc. 81; V.179; S.Lorenzo,Rio Grande Dr.H.v. Ihering [C. |}. 
C. 42) & yg. (Se. 29,383; do Sul. 
~  -V.174,176; C. 45, 38). 
f. Her. (Sc. 29; V. 180; Paraguay. Prof. Grant [P.}. 
C. 42 
g. 2 (Se. 35; V. 181; Asuncion, Paraguay. Dr. J. Bohls [C.]. 
C. 34 
h. 3 (Se. 31; V. 167; Rosaria, Argentina. LE. oy White, Esq. 
C. 41). [C.]. 
2% Q (Se. 83; V. 178; Argentina. Zoological Society. 
C. 41). 
‘ 
