SERPENTS. 



311 



the conformation of the skull and bones of the fiice, tlicy pre- 

 sent strong analogies with batrachian reptiles, and also with 

 fishes, one tribe of which, namely, theapodous oranguilliform 

 fishes, they greatly resemble by the length and flexibility of 

 the spine. These peculiarities of conformation may be in a 

 great measure traced to the mode of life for w^hich they are 

 destined. The food assigned to them is living prey, which 

 they must attack and vanquish before they can convert it into 

 nourishment. The usual mode in which the boa seizes and de- 

 stroys its victims is bycoilingthe hinder part ofits body round 

 the trunk or branch of a tree, keeping the head and anterior 

 half of the body disengaged; and then, by a sudden spring, 

 fasten upon the defenceless object of its attack, and twining 

 round its body so as to compress its chest, and put a stop to 



they exist concealed under the skhi. In others, he has discovered cartilagi- 

 nous filaments, which he conceives to correspond to these parts. (Annales 

 des Sciences Naturelles, VII. 170.) Some of these are represented in the 

 following figures. Fig. 203 exhibits the claw of the Boa constrictor y placed 



203 



205 206 



2or 



209 



at the termination of a series of bones, representing very imperfectly the 

 bones of the lower extremities. Fig. 204 shows the muscles attached to 

 these small bones. The three following figures, 205, 206, and 207, repre- 

 sent the claws and rudi mental bones of the Tortrix scijtak, Tortrix coral- 

 linus, ^Wil Anguis fragilis, respectively. Tliose of the Jmphisbaena alba, Fig. 

 208, and the Coluber pullatus. Fig. 209, are still less developed. The Clial- 

 cides, or snake lizard, which has four minute feet, is represented in Fig. 210. 



