THE RING SNAKE. 23 



which would be beyond the scope of this work, and 

 which can be studied in the larger text - books on 

 Zoology, a few of the more general anatomical points 

 of the ring snake may be noted. There are certain 

 negative points which are characteristic of the order 

 Ophidia. Thus there are no limbs, no external eye- 

 lids, no tear-ducts, no lips (only scales), no urinary 

 bladder, no epiglottis at the back of the tongue, no 

 sternum (the bone which the ribs join on to in some 

 animals). In addition to these general negative quali- 

 ties of the order the ring snake is also non-poisonous 

 and non-Irish; so that a good deal may be learnt about 

 this species by simply knowing what it is not. 



There is a complete covering of scales. Those on 

 the top of the head are characteristic of the species, so 

 must be noticed particularly. They are in the form 

 of large plates, and have a definite arrangement. This 

 arrangement may be expressed diagrammatically thus 

 (using the capital letter to represent a single 



plate) : — 



Nose. 







O 



00 



Eye. Eye. 



00 







Collar. 



This is the disposition of the largest plates, the relative 

 positions of the nose, eyes, and the yellow collar being 

 shown by the same words. There are other smaller 



