SERPENTS. 



51 



They heave long been divided into principal genera, Boa and Coluber, 

 distinguished by the simple or double plates on the under part of the tail. 

 The genus 



Boas*, Lin., 



Formerly comprised all those Serpents, venomous or not, the under part 

 of whose body and tail is furnished with uninterrupted, transverse scaly 

 bands, and which have neither spur nor rattle at the end of the tail. As 

 they are rather numerous, even after deducting from them the venomous 

 Serpents, they are again subdivided. 



The Boas, properly so called, have a hook on each side of the anus, a 

 compressed body, thickest in the middle, a prehensile tail, and small scales 

 on the head, at least on its posterior portion. It is in this genus that are 

 found the largest of all serpents; certain species attain a length of thirty 

 or forty feet, and are able to swallow dogs, deer, and even, as some tra- 

 vellers state, oxen, after having crushed them between their folds, covered 

 them with saliva, and enormously dilated their jaws and throat. This 

 operation is very protracted. One remarkable peculiarity of their anatomy 

 is, that their small lung is but half the length of the other. 



The integuments of the head and jaws of these serpents furnish ma- 

 terials for a still further subdivision. 



1. In some the head down to the tip of the muzzle is covered with 

 small scales, similar to those on the body, and the plates on the jaws are 

 not pitted. Such is the 



Boa constrictor, L. ; Ls Devin, Lacep. II, xvi, 1 ; Seb. I, xxxvi, 

 5, liii, 11, Ixxxviii, 5, xcix, 1, ci; Devin or Boa empereur of 

 Daudinf. Known by a broad chain, which extends along the back, 

 formed alternately by large, blackish, irregularly hexagonal spots, 

 and by pale oval ones, the two ends of which are emarginate, consti- 

 tuting a very elegant object. 



2. In others there are scaly plates from the eyes to the end of the 

 muzzle, but no fossulee on the jaws. 



Boa scytale and miirina, L. ; Anacondo, Seb. II, xxiii, 1, and 

 xxix, 1 ; B. aquatica, Pr. Max. liv. II. Brown ; a double suite of 

 round black spots along the back ; ocellated spots on the flanks. 



3. Others have scaly plates on the muzzle, and little pits of fossulte on 

 the lateral plates of the jaws. 



* Boa, the name of certain Italian Serpents of great size, most probably the four 

 striped Coluber, or Serpent of Epidaurus of the Latins. Pliny says they were thus 

 named, because they sucked the teats of Cows. The Boa, 120 feet long, which it is 

 pretended was killed in Africa by the army of Regulus, was probably a Python. 

 See Pliny, lib. VIII, cap. xiv. 



t Daudin thinks that the Devin is to be found in the eastern continent, but it is 

 certainly from Guiana. A'aillant and Humboldt have procured it there. Pr. Max. 

 has found it in Brazil. The two succeedino: species were also brought from Surinam 

 by M. Le Vaillant, and it is well known that the Bojobi inhabits Brazil. I do not 

 think there is any large Boa, properly so styled, in the eastern world. The great 

 Serpents of Africa and India are Pythons. The name Devin arises from the circum- 

 stance of having improperly applied to tiiis Serpent what is stated respecting certain 

 large Colubers, which constitute the Fetiches of some uegro tribes. 

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