-VS2 REPTILIA. 



The Boa,s mure pariiru]arly so iianind, liavc a hook on eacli siilc of the anus; a compressed body, 

 larger towards the middle ; a jireliensile tail ; and small scales, at least on tlu: hinder jjart of the head. 

 Among thorn are found the largest of all Serpents, certain speeii.-s attaining a length of thirty or forty 

 feet, and Ix'ing eapal.ile of swallov*'ing Dogs, Stags, and even Cattle, at least according to some naira- 

 tors, after ha\ing crushed theni within their folds, Inhricated them \\'\i\i their saliva, and enormously 

 dilated their jaws and gnllet. This operation lai^ts a long A\hile. A remarkable particular of their 

 anatomy consists in their having one lung but lialf shorter than the other. [At the extremity of the 

 great lung in all this tribe is an extremely capacious air-bag, the use of which appears to be for con- 

 taining the air requisite for respiration, when the nostrils arc closed by the tedious process of deghiii- 

 tion.] We subdivide these Serpents according to the teguments of the head and jaws. 



Some have the head covered as far as the tip of tlu' niu'AzU- with srnall scales resembling- those of the body, and 

 the plates which invest the jaws are not furrmveil with i^i-'.>oyvs. ( )tliers have scaly plates beneath the eyes as far 

 as the muzzle, and no furrows to the jaws. Some, again, have scaly plates upon the muzzle, and groo\-es upon 

 those of tlie sides of the jaws. There are some with plates on the muzzle, and the sides of the jaw hollowed into a 

 slit-like chink beneath the eye and further backward. And, lastly, some have no furrows, and the muzzle 

 invested with plates but slightly prominent, which are obliquely cut backwards in front and truncated at the tip, 

 so as to terminate in corners : these have the body much compressed, and the back keeled. They irdiabit the 

 East Inilies wliereas the others are from America, and should form a distinct subgenus — Ccncliris, Gray. 



The Scytals {Pseudoboa, Schneider). 



Plates, not only on the muzzle, but over the cranium, as in the Snakes proper ; no grooves, the body 

 round, and head even with the trunk, as in the Roles. 



Daudin has likewise separated 



The Ertx, — 

 "Which differ by having a very short obtuse tail, and by their ventral plates being narrower. The head 

 is short and nearly even with the body, characters in wdiich they approximate the Roles, -weie it not 

 that the conformation of their jaws permitted these to distend. The head is covered with small 

 scales; and th(;y have aho no hooks near the anus. 



TriH Erfktoxs, Lace^iede, — 

 Are very remarkable for having two soft jirominenccs covered with scales, at the tip of the muzzle; 

 head i)]atod ; the plates of the belly not v^ry wide, and thr)sc of the under-i)art of the tail dhfercnt 

 from the other scales. Their tail, however, i^ lotig and pointed. 



Tni^ Snakl;s Projier [Co!/i/jci\ Lin.J— 

 Comprehended all the s[)eeie3, venomous or non-venomous, the plates underneath the tail of which are 

 divided each into two, oi-, m other words, ranged in ]iairs. 



ludepcndcntly nf the subtraction nt* the venomniis kinds, their number is so vast that wc are oblii^eil to have 

 recourse to all sorts of characters in order to distini^iiibh them. First, are separated 



The Pythons, Daudin, — 

 Which have hooks near the anns, and narrow ventral plates, as in the Boas, from which fbev only 

 ditfcr by having the plates underneath the tail double. Their head is jilated at the lip of the luuzzle, 

 and their lips grooved. Species occur as large as any lloa. 



Some of these Pythons have the first, and others tlie terniii)al plates of their tail, simple ; but these are perhaps 

 accidental varieties. 



Tlie Cerheri, like the true Pythons, have the head entirely covered with smaU scales, with the exception of 

 plates between and before the eyes ; but tbey have no hooks near the anus. They li:i\e sutuetimes also simple 

 plates at the base of the tail. 



XenopeUiSy Re] n\ya.rdt; have great imbricated triangular plates before the eyes, which niii^ht be coid'oundcd 

 with the scales adjacent to them, only that tUe latter are smaller. 



//e^erot/oH, Beauvois.— The ordinary plates ot this group, but the tip of the muzzle composed of a short single 

 piece, in form a trihedral pyramid, which is a tittle raised and erected above, a conformation which has induced 

 the appellation of piij-snonted Serpents. 



nie //i/r/va, Daud. — Indian species, with sulieaudal iilates always simple, except those at the point, which are 

 double ; these trivial anotnalies, however, niei'it but little notice. 



The Dipsas of Laurenti {Bunffann;, Oppel.)— Body compressed, and very much larger than the head : the rauffc 

 of scales along the spine of the back larger than the others. 



Dendrophis, Fitzinger; Ahcclulla, Gray.— Resemble the last by having a range of broader scales aloni; the back, 

 and narrower scales along the flanks ; but their head is not wider than the body, which is slender and very much 

 len'^thened. Muzzle obtuse. 



