PYTHONS AND BOAS. 



181 



The Pythons and Boas. 



Family BoiD^. 



Including the largest of living snakes, this family is now regarded as being 

 the most generalised of the entire suborder (exclusive of the blind - snakes), all 

 the others presenting such characters as would admit of their having taken 

 origin from ancestral types belonging to the one under consideration. In 

 common with the remaining families, the boas and pythons differ essentially 



INDIAN PYTHON CRUSHING ITS PREY (j\ Hat. Size). 



from the blind-snakes in that both jaws are fully toothed, and likewise in the 

 presence of a transverse bone to the palate. The characters specially dis- 

 tinguishing the present from the other families of the suborder are. un- 

 fortunately, largely derived from the structure of the skull, and therefore 

 require some degree of anatomical knowledge for their proper appreciation, while 

 they cannot be described without the use of a considerable number of technical 

 terms. It may be mentioned, however, that the lower jaw has on the inner side 

 of each branch a thin bone known as the coronoid : while on the top of the skull 

 the prefrontal bones, which lie on the outer side of the forepart of the frontals, 

 articulate with the nasal bones, or those roofing the front of the cavity of the nose. 

 In the hinder part of each side of the skull lies a large bone, termed the supra- 



