15. Boa. 119 
4. Boa imperator. 
Boa im Gray, Oat. 9.101 C849) « dork ; Dum. § Bibr. vi. p. 519 
ei a, Perk nat Ge Jan, Icon. Gén. p. 81, 1.6, pl. i. 
(1864) ; at Miller, erh. nat. Ges ‘Basel, vi. 1878, p. 650; Bocourt, 
Miss, Se. Mex., Rept p- 519, dq xxx, fig. "8 (1882); Garm. N. Am. 
Rept. p. 8 (1883) ; U.S. Nat. Mus, no. 32, ¥887, p. 65. 
BP ues, Lyd. ee Bonite, Zool. i. p. 144, "Rept. pl. iv. 
(1841); Dum, Bibr. t. ¢. p. 521; Gray, lc. ; Cope, Proc. Ac. 
Philad. 1861, p. 808; Jan, 1. c. p. 82, 1. 6, pl. ii. 
—— ortonii, Cope, Proc. Am. Philos. Soc. xvii. 1878, p. 35. 
— constrictor, var. isthmica, Garm. l. ¢. p. 9. 
Snout scarcely prominent. Rostral as broad as deep, not visible 
2 from above ; symphysial at least as long as broad ; head-scales small, 
-" sometimes slight] enlarged on the snout; an enlarged loreal some- 
as times present, in font of the preoculars, one of which is more or less 
ialaresd - 15 to 18 scales across the forehead, from eye to eye; 14 
to 20 scales round the eye, which is separated from the labials by 
one or two series of scales; 18 to 21 upper labials. « Scales in 61 
to 79 rows. Ventrals 225-252; anal entire; subcaudals 47-65. 
Coloration as in B. constrictor, but no red on the tail, and dorsal 
cross bars more numerous, viz. 22 to 30 on the body; the dark 
line on the middle of the head usually with a process on each side 
between the eye, thus forming a cross. 
Total length 2800 millim. ; tail 280. 
Mexico to Western South America (Colombia to Peru). 
a. 7 Sc. 79; V.238; Ventanas, Mexico. Hr. A. Forrer [C.]. 
C. 59). 
b. og nag 69; V.235; Atoyac, Mexico. Mr. H. H. Smith [C.}. 
F. D. G 
ed. 9 (Se. 67; V. 289; 8. Mexico. FD Godin, Esq, 
C. 54) & hgr. (Se. 79; (P.). 
V. 248; C. 53). 
@ & (Se 69; V. 283; Mexico. M. Salls [C.]. 
f Ye, be 69; V.242; Mexico. E. Cooke, Esq. [P.]. 
9. Ye. (Se. 71; V. 225; Mexico 
h. 2 (Sc. 65; V. 236; Vera Paz, 1 O. Salvin, Esq. [C.}. 
ca. yd a Ae. 
i 2 (Se. 9; V. 242; Guatemala. O. Salvin, Esq. [C.]. 
k. oS. cin (Se. 69; V. Costa Rica. F. D. Godman, Esq. 
C. a 
i. Her. ¢ 3 cs 79; V. Esmeralda, Ecuador. wei r[C.}. 
65). 
m. Y, fe, 71; V.231; N.W. coast of S. Lieut. Wood [P.]. 
0. 3). America. 
n, - ies, stffd. Tropical America. 
5. Boa mexicana. 
Boa mexicana, Jan, Icon. Gén. p. 82 (1864); Bocourt, Miss. Sc. 
Mex., Rept. p. 520, pl. xxx. fig. 9 (1882). 
— divi iloquax, var. mexicana, Jan, op. cit. 1. 5, pl. iv. 
