208 
SNAKES. 
this well-known species extends from India to Java. Common everywhere in 
India, and feeding on mammals, birds, and frogs, the rat-snake derives its name 
from its habit of entering houses in search of rats and mice. Like its allies, it is 
fierce and always ready to bite; and old specimens brought to Europe never become 
tame. When irritated, it utters a peculiar sound, which has been compared to that 
produced by gently striking a tuning-fork. A smaller allied Indian species (Z 
corrus ) differs by having the scales arranged in fifteen, instead of seventeen rows. 
Nearly allied to the preceding are the American running snakes, 
Eunmng Snakes. ^ ^ pantherine snake (Ptyas pantlierinus) is a familiar 
and handsome example. From the last genus the running snakes are chiefly 
BLACK-MARKED AND HORSESHOE SNAKES Q nat. size). 
distinguished by their teeth and the larger size of the eyes. They are all large 
and powerful reptiles, with cylindrical body, clearly defined head, large eyes, 
regularly tapering tail, which is at least equal to a fourth of the total length, the 
scales smooth and arranged in from fifteen to seventeen rows, normally-arranged 
head-shields, unkeeled inferior shields, and about twenty-one equal-sized teeth in 
the hinder upper jawbone. The pantherine snake, which is an inhabitant of the 
hottest regions of the Guianas and Eastern Brazil, and is especially common in the 
neighbourhood of Rio de Janeiro, is characterised by having fifteen rows of scales 
on the body, the lack of the small lower preorbital shield, and its general form and 
coloration; its length being as much as 7 feet. The ground-colour is yellowish 
grey on the upper-parts; on the front of the head are three dark crossbars, while 
two broad longitudinal stripes run along the hinder part of the head and neck; 
