152 COLUBRID. 
Frontal once and one third to once and a half as long as broad, 
nearly as long as or shorter than its distance from the end of the 
snout, as long as or longer than the parietals; an azygous shield 
separates the prefrontals; eye usually encircled by three to five 
shields, in addition to the supraocular; temporals 1+2; seven 
upper labials, third or fourth rarely entering the eye; four or five 
lower labials in contact with the anterior chin-shields ; posterior 
chin-shields small. Scales in 21 rows. Ventrals 131-147; anal 
divided ; subcaudals 29-44. Yellowish or pale brown above, with 
three series of large black or brown black-edged spots ; three black 
A-shaped bands on the head and a larger one on the nape; lower 
parts black and yellow (red?), the two colours in nearly equal 
proportion. 
Total length 560 millim.; tail 80. 
Southern Brazil, Paraguay, Uruguay, Argentina, Southern 
Chili. 
-c. 5 BG 136; C. 40), Rio Grande do Sul. Dr. H. vy. Ihering [C.]. 
ae (V. 131; C. 29), & 
e. (V. 145; C. 40). 
d. 3 (y: 134; C. 41). San Lorenzo, Rio Dr, H. v. Ihering [C.]. 
Grande do Sul. 
e-g. & (V. 148; C. 44) Dept. of Soriano, R. Havers, Esq. [P.]. 
& yg. (V. 136, 145; C. Uruguay. 
35, 40). 
h-t. 3 (V. 141; C. 48) Montevideo ° 
& 9 (V. 182; C. 33). 
: Q (V. 135; C. 38). Buenos Ayres. G. Wilkes, Esq. [P.]. 
Teo ( ¥. 188% a, 36). Buenos Ayres. 
m—N. “4 (V. 147; C. 39) Argentina. Mr. Wilson [C.]. 
a 2 (VY. ae C. 36). 
O.ape(V. 1 133 C, 34). 8. Chili. A. Lane, Esq. [C.]; 
H. B. James, Esq. [P.]. 
p. Skull. Argentina. 
2. Lystrophis histricus. 
Heterodon histricus, Jan, Arch. Zool. Anat. Phys. ii. 1863, p. 224, 
and Icon, Gén. 7G pl. iv. fig. 2 (1865); Steindachn. Verh, zool.- 
bot. Ges. Wien, 1864, p. 232, pl. vi. 
nattereri, Steindachn. Novar a, Rept. p. 90 (1867). 
Frontal as long as broad, shorter than its distance from the end 
of the snout, as long as the parietals ; no azygous shield separating 
the prefrontals ; one (or two) pre- and two (or one) postoculars ; 
temporals 14+ 2; seven upper labials, third and fourth entering the 
eye ; five lower labials in contact with the anterior chin-shields ; 
posterior chin-shields small. Scalesin 19 rows. Ventrals 133-144 ; 
anal divided ; subcaudals 27-37. Reddish above, with more or less 
regular black cross bars edged with yellowish; sides yellowish, 
spotted with black ; three black A-shaped bands on the head, and a 
larger one on the nape; yellowish-white inferiorly, spotted with 
black. 
