the ventrals (Fig. 8). These are snakes with narrow ventrals, 

 as opposed to the typical snake which has broad ventrals. 



Again some snakes have no ventrals at all. The belly 

 and the back are covered with identical small scales. 



In another group of snakes again the normal head 

 shields are wanting and the snout and crown are covered 

 with small scales just hke the back of the snake (Fig, 9). 

 These are snakes having scaly heads, not shielded heads, 

 as the typical snake has. Some of these scaly-headed 

 snakes have one or more small shields, e,g., a supra-ocular 

 or nasal ; and the labials can be made out as a rule ; but 

 they can be seen at once to be quite different from the snake 

 with a normally shielded head. 



All snakes are covered with scales, but these variations 

 in the different kinds of scales on head and belly enable us 

 to classify snakes into four very useful groups as we shall see 

 in the next chapter. 



CHAPTER ly. 



THE FOUR GROUPS OF SNAKES. 

 Group I, — Snakes with no ventrals. 



The snakes in this group may have shielded heads or 

 scaly heads but their bellies like their backs are clothed 

 with scales. 



The snakes in this group are all harmless. 



. Group II. — Snakes w^th narrow ventrals. 



These again may have shielded or scaly heads but the 

 belly is covered with transverse plates which do nob extend 

 completely across ; so that when the specimen lies on its back 

 the last row, and generally several rows, of scales are seen 

 on each side of the ventrals (Fig. 8). 



The snakes in this group are all harmless. 



