THE CO LU BRINE SNAKES 2571 



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 taken 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, of 

 which the pantherine snake (Ptyas pantherinus} is a familiar and 

 handsome example. From the last genus the running snakes are 

 chiefly distinguished by their teeth and the larger size of their 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 

 neighborhood of Rio de Janeiro, is characterized 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 seven feet. The ground color is yellowish 

 gray 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; the 

 ornamentation of the back takes the form of a row of large grayish-brown black- 

 edged spots, which are lozenge shaped on the neck, but further back become irregu- 

 lar, and confluent with two lateral rows of spots. The yellowish-white shields of 

 the edges of the jaws have black lines of division, and behind each eye a blackish- 

 brown streak runs to the angle of the mouth. This snake frequents swampy situa- 

 tions well covered with trees and bushes, and is remarkably swift and active in its 

 movements. In its general habits it appears to resemble the ringed snake, feeding 

 almost entirely on frogs and fish. 



The typical representatives of the family are the climbing snakes, of 

 Snakes which there are a large number of species, distributed over the greater 

 part of Europe, Asia, and North and tropical America. Agreeing 

 with the preceding genus in having the teeth in the hinder upper jawbone of nearly 

 equal size, the climbing snakes have from twelve to twenty-two of these teeth, the 

 teeth of the lower jaw being likewise subequal; and they are further specially distin- 

 guished by having the scales of the body arranged in from fifteen to thirty-five lon- 

 gitudinal rows, and furnished pits at their extremities, those in the middle line of 

 the back not being larger than the others. The long head is well defined from the 

 neck, with a moderate-sized eye, of which the pupil is circular, and the shields nor- 

 mally arranged; the elongated body is slightly compressed, with its scales either 

 smooth or keeled; and whereas the shields on the lower surface of the body usually 

 have a more or less well-marked keel on the side, those of the tail are arranged in a 

 double row. All these snakes are fierce in their disposition, and while all can 

 climb well, some are almost entirely arboreal; others again, frequent the neighbor- 



