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 
fioridana) 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 (Opbisaurus 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 an 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 Marocco, 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. 
