REPTILES OF FLORIDA 173 



another most primitive amphibian, is likewise confined to 

 the south-eastern States, while Siren lacertina has its head- 

 quarters in the same region. A very striking amphibian is 

 the Florida tree frog (Hyla gratiosa), the largest tree frog of 

 North America, which is common in Florida, extending from 

 there across the borders of Georgia and Mississippi. 



The most remarkable member of the fauna of Florida, from 

 a zoogeographical point of view, is one of the worm-lizards 

 (Amphisbaenidae). The Florida worm-lizard (Rhinema 

 floridana) is a limbless, blind, worm-like creature which 

 spends its entire existence under ground. It is no doubt of 

 immense antiquity, and the only member of the family known 

 from North America. 



Whether the curious glass-snake (Ophisaurus ventralis) has 

 originated in the south-west or south-east is a difficult pro- 

 blem which future researches may help to solve. Professor 

 Cope * speaks of art eastern and western type, and it may 

 possibly have spread northward from two independent centres. 

 I need scarcely mention that the glass-snake, like the Euro- 

 pean slow-worm, is a limbless lizard. Anyone may convince 

 himself of this fact by examining the eyes, which possess 

 well -developed eyelids, while the presence of ear openings 

 also distinguishes these creatures from true snakes. The 

 particular point of interest in the presence of the glass-snake 

 in America lies in the circumstance that a closely allied 

 species (0. apus) inhabits Marocoo, the Balkan Peninsula 

 and Asia Minor, while a second glass-snake is known from 

 the eastern Himalayas and Burma. This extremely discon- 

 tinuous range denotes great antiquity. The glass -snakes, 

 moreover, live principally underground, and, like the worm- 

 lizard, are not liable to accidental conveyance by any of the 

 occasional means of dispersal that we hear so much of. Their 

 occurrence on both sides of the Atlantic gives great weight 

 to the evidence, cited in previous chapters, of the former exist- 

 ence of a land bridge right across the middle of the Atlantic. 

 I need not discuss the subject any further now, because it will 

 be amply dealt with in some of the succeeding chapters, when 

 new arrays of facts in support of my contention will be sub- 



* Cope, E. D., " Crocodilian?, Lizards and Snakes," p. 496. 



s ' 



