Bye. g ae 29; V. 211; 
66) & her. ’ (Se. 26, 
57 V. 204, 211; C. 71, 
é. a Ne 25; V. 197; 
¢. a (Sc. 25; V. 190; 
2 Se. 25; V. 2038; 
6. “ Bc. 23; V. 194; 
t. ¢. (i. 23; V. 205; 
a a Ne 23; V. 197; 
C. 60 Q (Se. 25; V. 
908; G. 64), & yg. (Se. 
25 ; V, 190; C. 63). 
v, #3 ° Q (Se. 23; V. 216; 
CG. 61) & her. (Se. 23, 
25 ; V. 204, 206; C. 
66, ’61). 
7. ome Mai 23; V. 195; 
p. ‘fier, Se. 25; V. 194; 
0.74). 
or. Yg. (Se. 23, 25 ; 
V. 207, 180; 0.58, 66), 
v. Yg. (Se. 27; V. ‘181; 
C. 71). 
. nee (Se. 33; V. 229; 
C. 58 
x: a (Se 81; V. 225; 
C. 69). 
y. Skeleton. 
o. Skeleton. 
a’, Skull. 
6’. Skull. 
11. LACHESsIS. 
Demerara. 
Demerara. 
Para. 
Pernambuco. 
Rio Janeiro, 
Rio Janeiro. 
Porto Real, Prov. 
Rio Janeiro. 
Brazil. 
Madre de Dios, 
Bolivia. 
Pampa del Sacra- 
mento, Peru. 
W. Ecuador. 
Ecuador. 
-——— P 
—? 
Martinique. 
S. Ameria. 
S. America. 
C. America. 
537 
Col.Sabine[P.]. (Types 
of B. sabinit.) 
Dr. Hancock [P.]. 
R. Graham, Esq. [P.]. 
W. A. Forbes, Esq.[P.]. 
Mr. Fry [P.]. 
Haslar Collection. 
M. Hardy du Dréneuf 
[C.]. 
Lord Stuart de Roth- 
say [ P.]. 
Mr. W. Davis [0. : 
Messrs. Veitch [P.]. 
Mr. Fraser [C.]. 
E. MacLeay, Esq. [P.]. 
(Type of B. cinereus.) 
(Type of B. megera.) 
This species may have to be united with the following. The 
only character by which I have distinguished the two, viz., the 
length of the keel on the dorsal scales, is not dependent on age or 
sex, as had been supposed. Some specimens of ZL. lanceolatus, 
however, approach L. atrox in the swelling of the scales at the 
base of the keels, and are thus intermediate between the two sup- 
posed species. It is also not impossible that two or three species are 
confounded here under JL. lanceolatus, but I have been unable to 
trace any limits or to find any correlation between the modifications 
in scaling and coloration. 
3. Lachesis atrox. 
sii atrox, Linn, Mus. Ad. Frid, pl. xxii. fig. 2 (1754), and 8. N. 
i. p. 883 (1766). 
Vipera atrox, Laur. Syn. Rept. p. 103 (1768). 
