276 CLASS XV. 



Boa L. Head distinct from trunk, flat above, elongato- 

 cordate or oblongo-trigonal, obtuse at tlie apex, covered witli 

 scales or anteriorly with scutes. Eyes moderate. Teeth in 

 intermaxillary bone none. Subcaudal scutes entire. Tail pre- 

 hensile. 



Sp. Boa constrictor L., Seba Thesaur. i. Tab. 53, fig. i, Merk. Beitr. 11. 

 Tab. I. Cuv. a. Ani., 6d. ill., Rept. PI. 26, fig. 3; the head entirely 

 covered with scales, no pit in the marginal scutes of the upper lip. This 

 prettily coloured species, of which the name is in general use as that of a 

 gigantic snake, is, however, by no means the largest species of this family, 

 and seldom attains a length of more than 10 feet ; it bears on the east coast 

 of Brasil, according to the Prince Maximilian van Wied, the name 

 of Jiboya, as does also the Boa cenchria L., Maxim. Ahi. Lief, vi., which 

 climbs trees and never lives in water ; this species has scutes on the head and 

 little grooves at the margin of the upjier jaw. The largest species, on the 

 contrary, is Boa murina L., Eunectes marl iiusWagu, Boa aqiuUica'NLxXl'Mi. 

 Abb. Lief. 11, Boa aboma Daud. Rej^t. V. PI. 62, fig. 2, PI. 63, fig. 2, which 

 attains a length of more than 20' ; it resides much in water, and, besides 

 fish, lives also on mammals that come to the banks of rivers to drink. 

 A very beautifully coloured species, blue-green with white bands, has 

 a compressed body ; Boa canina L., {Xiphosoma caninum Wagl.), Mus. 

 Ad. Frid. Tab. 3, Lac. Quadr. ovip. et Serp. 11. PI. 17, fig. i, Guer. 

 Iconogr., Rept. PI. 19, fig. 2. All these species are found in South 

 America. There are also, however, some species in the eastern hemisphere ; 

 Boa carinata Schn., Enygrus carinaius Wagl., from the island Amboyna 

 and New Guinea, and Enygrus Bibroni Dumer. from the island Viti or 

 Fejee, with scales carinate and larger than in the other species, where they 

 are usually very small. Also there is a Boa of the division or the 

 sub-genus Xip>hosoma, and another species that lives in water from which 

 Ddmeril and Bibron form their genus Pclopliilas, which have been 

 observed on the Island of Madagascar. 



Note. — On the divisions of this genus, to which almost 20 species belong, 

 into numerous sub-genera {Enygrus Wagl., Leptoboa DuM., BiBB., Tropi- 

 doplds DuM., BiBR., Eunectes Wagl., &c.) compare DuM., Bibr. Erpctol. vi. 

 PP- 474-5'56. 



Platygaster Dum. and Bibr., Urolepfis FiTZ. Head scutate, 

 conical, scarcely distinct from body. Scales cai'inate. Ventral and 

 subcaudal scutes broad. (Pits at lips none. Habitus of Coluber.) 



Sp. Boa pseudo-eryx nob., Platygaster muUicarotatu-sDvM. and Bibr., Tortrix 

 ])seudo-eryx Schlegel, Abbild. Tab. 34, New Holland. 



Python Daud. (Spec, of Coluber L.) Teeth in intermaxillary 

 bone four. Head distinct from trunk, elongate, truncate, anteriorly 

 scutate, posteriorly often scaly. Tail prehensile, with all or most 

 of the scutes below in pairs. Scales small, smooth. 



