116 BOTD^. 



e, f. Yg. (Sc. 69, 61 ; V. 248, Brazil. 



'251; C. 64, 71). 



ff, h. Ad., stffd. S. America. 



i. Hgr., skel. S. America. 



k. Hgr., skull. Cayenne. 



15. BOA. 



Boa, part., Linn. iSyst. Nat. i. p. 373 (1766) ; Schleg. Phys. Serp. ii. 



p. 373 (1837). 

 Constrictor, Laur. Syn. Rept. p. 106 (1768). 

 Boa, Wagl. Syst. Amph. p. 169 (1830) ; Dtim. 8f Bihr. Erp. Gen. vi. 



p. 500 (1844) ; Gray, Cat. Sn. p. 99 (1849) ; Jan, Icon. Gen. p. 80 



(1864) ; Bocourt, Miss. Sc. Mex:, Rept. p. 517 (1882). 

 Draco {non Law.), part., Oken, Lehrb. Natury. iii. p. 273 (181G). 

 Pelopliilus {nun Dej.), Dum. 8f Bihr. t. c. p. 523 ; Gray, I. c. p. 101 ; 



Jan, I. c. p. 84. 

 Acrantophis, Jan, I. c. p. 82; Bocourt, I. c. p. 521. 



Anterior maxillary and mandibular teeth longest, gradually 

 decreasing in size. Head distinct from neck, covered with small 

 scales, with or without enlarged shields on the loreal and supra- 

 ocular regions ; nostril between two or three nasals. Eye rather 

 small, with vertical pupil. Body cylindrical or feebly compressed ; 

 scales very small, smooth. Tail short, more or less prehensile ; sub- 

 caudals all or part single. 



Tropical America ; Madagascar. 



Synopsis of the Species. 



I. Loreal region with small scales or a single small shield ; sub- 



caudals 45 to 69. 

 Scales in 81 to 95 rows on the thickest 



part of the body ; ventrals 234-243 ; 



rostral a little broader than deep ; syni- 



. physial at least as long as broad 1. constrictor, p. 117. 



Scales in 65 to 87 rows ; ventrals 242-251 ; 



rostral as deep as broad ; symphysial 



broader than long 2. occidentalis, p. 118. 



Scales in 65 to 75 rows ; ventrals 258-275 ; 



rostral a little broader than deep ; sym- 

 physial at least as long as broad 3. diviniloqiux, p. 118. 



Scales in 61 to 79 rows ; ventrals 225-252 ; 



rostral as deep as broad ; symphysial at 



least as long as broad 4. imperator, p. 119. 



Scales in 55 rows 5. mexicana, p. 119. 



II. Loreal region with several shields ; subcaudals 20 to 41. 

 Scales in 59 to 65 rows ; subcaudals 20 



to 33 6. dumerilii, p. 120. 



Scales in 69 to 77 rows ; subcaudals 34 



to 41 7. madagascariensis, 



[p. 120. 



