15. BOA. 117 



1. Boa constrictor. 



Linn. Amcm. Acad. i. p. 497, pi, xvii. fig. 3 (1749). 



Boa constrictor, Linn. S. N. i. p. .373 (17G6) ; Sclmeid. Denkschr. Ak. 



Miinch. vii. 1821, p. 114, pi. vi. fig. 1 ; Wied, Beitr. Nat. Bras. i. 



p. 211 (1825) ; Dum. iif Bibr. vi. p. 507 (1844) ; Gray, Cat. p. 100 



(1849) ; Ja7i, Icon. Gen. p. 81, 1. 6, pi. i. (1804). 

 Constrictor formosissimus, Laur. Syn. Rept. p. 107 (1768). 



rex-serpentum, Laur. I. c. 



auspex, Laur. I. c. p. 108. 



Boa constrictrix, Sclmeid. Hist. Amph. ii. p. 247 (1801). 



constrictor, part., Daud. Rept. v. p. 174 (1803); Schleg. Phys. 



Serp. ii. p. 373, pi. xiv. figs. 6 & 7 (1837). 



Snout slightly prominent in the adult, ohliquely truncate in the 

 young. Eostral 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 prajoculars slightly enlarged ; 18 to 24 scales 

 across the forehead, from eye to eye ; 1(5 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. Yentrals 234- 

 243 ; anal entire ; subcaudals 49-GO. 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. 



«, b. Yg. (Sc. 89, 87 ; V. 238, Tobago. W. A. Ludlam, Esq. 



237; C. 49, 55). [P.]. 



c. Yg. (Sc.95; V.240;C.50). Trinidad. 



d. Yg. (Sc. 93 ; V. 239 ; C. 54). Cavenne. 



e. S (Sc. 89 ; V. 238 ; C. 5G).' Pa'ra. J. P. Smith, Esq. [P.]. 

 /. Yg.(Sc.87; V.243;C.51). Pemambuco. W. A. Forbes, Esq. 



g-h. Yg. (So. 85, 85 ; V. 241, ^[oyobaniba, Mr. A." H. RofF [C.l. 



238 ; C. 50, 60). N.E. Peru, 



i, k, I. 2 & hgr., stffd. S. America. 



n. Ad., skel. Trinidad. Lord Harris [P.]. 



n. TIgr., skel. — — ? 



0. Hgr., skull. Cayenne. 



