15. Boa. 117 
1. Boa constrictor. 
Linn. Amen, Acad, i, p. 497, pl. xvii. fig. 3 (1749). 
Boa constrictor, Linn. 8. Ni, p. 873 (1 66); Schneid. Denkschr. Ak. 
Miinch, vii. 1821, p. 114, Lv. fg Wied, Beitr. Nat. Bras. i. 
211 (1825) ; Dum. §& B . 507 (1844) ; Gray, Cat, p. 100 
{is4g) ; —, Icon. Gén. . Sl, 1 pl. i. (1864). 
Constrictor f ormosissimus, Laur. Syn. Shace Pp. 107 (1768). 
SBibenies. see gy mening a 
Laur, l. ¢. 
Boa constrictrix, fn Gohncid. His Hist Amph, ii. Right 
—— constrictor, t. v. Schleg. Phys. 
Serp. ii. p. Sri ol civ fe figs. 6 S6k7 (1437). Om) Sg 
Snout slightly prominent in the 9 cbdacile truncate in the 
young. Rostral a little broader than deep; symphysial at least 
as long as broad; head-scales small, slightly larger on the snout; no 
shields; one of the preeoculars slightly enlarged; 18 to 24 scales 
across the forehead, from eye to eye; 16 to 20 scales round the eye, 
which is separated ‘from the labials by two or three series of scales ; 
21 to 25 upper labials. Scales in 81 to 95 rows. Ventrals 234— 
243; anal entire; subcaudals 49-60. Pale brown above, with 15 
to 20 dark brown cross bars widening on each side and, if connected 
by a dark dorso-lateral streak, enclosing large elongate oval or 
elliptical spots of the pale ground-colour; a light longitudinal line 
in the outer widened portion of the dark cross bars; on each side a 
series of large dark brown spots with light centres, most of which 
alternate with the dorsal bars; on the tail the markings become 
much larger, brick-red, edged with black, and separated by narrow 
yellowish interspaces ; head with a dark brown median line extend- 
ing from between the nostrils to the nape, widening behind, some- 
times loop-shaped; a crescentic blackish marking on the rostral ; a 
dark brown streak on each side of the head, passing through the 
eye, and sending down a process between the end of the snout and 
the eye; a dark brown bar below the eye and two on each side of 
the lower lip; belly yellowish, dotted, or dotted and spotted with 
black. 
Total length 3355 millim.; tail 330. Reaches to 12 feet 
( Wied). 
South America, from Venezuela to Buenos Ayres. 
a, b. Yg. (Se. 89, 87; V. 238, Tobago. W. A. Ludlam, 
” 997. "0, 49, 55). (P.} ital 
ce. Yg. (Se. 95; V. 240; C, 50). Trinidad. 
d. Yg. (Sc. 93; V. 239; C.54). Cayenne. 
e. ¢ (Sc. 89; V. 238; C.56). Para. 7 P. Smith, Esq.[P 
f. Yg. (Se. 87; V. 243; 0.51). Pernambuco. ip Vepy Forbes, 
g-h. Yg. (Sc. 85,85; V.241, Moyobamba, Mr. A. H. arcs 
238 ; C. 56, 50). .E. Peru, 
i,k,l. 2 & hgr., stfid. S. America. ; 
m. Ad., skel, Trinidad. Lord Harris [P.}. 
n. Hr., skel. —-? 
o. Hgr., skull, Cayenne. 
