82 REPTILES. 



Fam. IV. BoiD^. 



The ventral shields narrow (except in Bolyeria), transverse, 

 hand-like, often six-sided ; the hinder limbs developed under the 

 skin, formed of several bones and ending in an exserted horny spur, 

 placed one on each side of the vent. Tail short, generally prehen- 

 sile. The pupil oblong, erect, except in Tortrix. 



They live in marshy places : fixing themselves by the tail to 

 some aquatic tree, they allow themselves to float, and thus entrap 

 the animals which come to drink : they kill their prey by pressure. 

 The spurs were first noticed by Dr. P. Browne {Hist. Jam. 1789, 

 461). Schneider {Hist. Amph.) again observed them in 1792, and 

 Dr. Russell figured them in 1795. 



Constrictores and Anguiformes pars, Oppell, Rept. 1811. Co- 

 lubrini pars, Boie, Isis, xx. 510, 1827. Boida?, Gray, Ann. Phil. 

 1825, 209. Zool. Misc. 41, 1840. Boidae and Erycidae, Bonap. 

 Acad. Roy. Turin, 1840. Ilysioidea and Pythonoidea, Fitz. N. 

 Class. Rept. 26, 27, 1826. Serp. Macrostomata, Isodonta, and part 

 Holodonta, Muller, in Tiedem ^ Treviran. Zeitsch.fur Phys. 1832, 

 iv. 263. Serp. Phenopodes, Meyer. Ophidiens azemiophides, ou 

 Serpents non Veneneux Auriformes ou Vjihomens, Dumeril ^Bih. 

 Erp. Gen. vi. 337, 380. Colubrinia aplepia, Rafin. Anal. Nat. 77, 

 1815. Fam. Boas, Schlegel, Phys. Serp. Saurophidia pars, fam. 

 Cylindrophes, Gongylophes, Centrophes and Pythophes. Fitz. Syst. 

 Rept. 14, 1846. 



Synopsis of the Genera. 



I. Tail prehensile, strong. Head distifict : muzzle truncated. 



A. Subcaudal plate two-rowed ; intermaxillary or incisive teeth dis- 

 tinct ; superciliary bone distinct. Old World. Pythonina. 



1. MoRELiA. Upper and lower labial shields deeply pitted ; muz- 



zle with symmetrical shields. 



2. Python. Upper and lower labial shields deeply pitted ; muz- 



zle and forehead with symmetrical shields ; nostrils vertical. 



3. HoRTULiA. Upper and lower labial shields deeply pitted ; 

 muzzle and forehead with svmmetrical shields : nostrils late- 

 ral. 



