52. KEPTILiA. 



ORDER III. 



0PHIDIA.(1) 



Serpents are reptiles without feet, and consequently those 

 which best merit that appellation. Their extremely elongated 

 body moves by means of the folds it forms when in contact 

 with the ground. They are divided into three families. 



FAMILY I. 



AXGUINA.(2) 



The Angues still have an osseous head, teeth, and tongue, 

 similar to those of a Seps; their eye is furnished with three 

 lids, <5cc., and, in fact, if we may so express it, they are Sepes 

 without feet : they arc all comprised in the genus 



Akguis, Lin. 



Characterized externally by imbricated scales, with which they are 

 completely enveloped. They have been separated into four subge- 

 neraj in the three first we still find beneath the skin the bones of the 

 shoulder and pelvis. 



PsEUDOPUs, Merr. 



The tympanum visible externally, and on each side of the anus a 

 small prominence(3) which contains a little bone analogous to the 

 femur, connected with a true pelvis concealed under the skin. The 

 anterior extremity hardly shows itself externally, its only mark be- 

 ing a fold not easily detected; it has no internal humerus. One of its 

 lungs is a fourth less than the other. The scales are square, thick, 

 and semi-imbricate, some of which, between those on the back and 

 those on the belly, being smaller, occasion a longitudinal furrow on 

 each side. 



(1) 0<fif, a Serpent. 



(2) Anguu, the Latin generic term for Serpents. 



(3) Pseudopus, i. e. false foot. 1 have never been able to discover any division 

 of the extremity of this very small vestige of a foot. M. Schneider has been 

 equally unsuccessful. 



