HISTORY 
OF 
THE AMERICAN FAUNA. 
REPTILES. 
'I’his, the third class in the descending series of tlie 
Animal Kingdom, derives its name from the Latin 
reptare, to creep, indicating one of the most charac- 
teristic features of the group. Eeptiles are cold- 
blooded, with a heart of three chambers, containing 
two auricles and one ventricle; the latter being 
sometimes divided by a fleshy septum. 'I’he circula- 
tion is sluggish. The venous blood being in all more 
or less commingled with arterial, the temperature 
is, consequently, low. 'J'he respiration is by lungs. 
The Frogs and Toads — Batrkchians, or Amphibians 
— which were once included in the class Reptilia, 
some of which breathe at one period of existence by 
bronchial or gill-like organs, now form a separate 
class. The brain of Reptiles is small, comparatively ; 
there is no corpus callosum, but a small anterior 
commissure is present. 'I'he reproductive system is 
varied, according to the orders ; the cloaca is always 
present. The ova in some hatch within the body, 
but in most they are expelled, and left to develop 
in the heat of the atmosphere. 
The term Herpetology is in use to designate the 
study of Reptiles and Amphibians. Little atten- 
tion was given to this branch of Natural History in 
ancient, or even later times, as compared with other 
classes. After a meagre attempt by Aldrovandus 
and Gesner, Ray recorded the first really useful 
knowledge on the subject. Since this, several emi- 
nent writers have made it a special study. In our 
country, Holbrook, Baird, and Girard and Cope have 
accomplished very much to bring order out of the con- 
fusion of material. Agassiz’s work. Contributions 
to the Nat. Hist, of the United States, is notably 
a great advance, containing a vast amount of matter 
relating to this subject. In Europe Dr. Schreber is 
authority of most note. The wonderfid discoveries 
in Palaeontology have both increased the numbers 
of the orders and the labor of correctly defining them. 
The most recent authors enumerate these orders as 
follows — where it will be seen, by noting the itali- 
cised names, which are those of extinct orders, that 
an extraordinary increase of knowledge has already 
been realized : 
Order — Ceocodilia. 
“ Laceetilia. 
Chelonia. 
“ Ophidia. 
“ Ichthyosauria. 
Order — Plesiosaurus. 
Dicynodontia. 
“ Pterosauria. 
“ Dinosauria. 
Order — TESTUDINATA. 
T’he Turtles. 
The term Chelonia is sometimes used to designate 
this order ; its meaning is, simply, from the Greek, 
a Tortoise. The latter word is derived from tortus, 
alluding to the foun of the feet or legs. The char- 
acteristic features of the 'I’urtles are very familiar 
and apparent. They are bodies enclosed between 
two bony shields, which are more or less developed : 
the upper called the carapace, and the lower the 
plastron. The only flexible portions of the spine 
are those including the vertebrae of the neck and 
tail. The carapace — its bony part — is formed by a 
mingling of the dorsal and sacral vertebrae and the 
ribs, and a series of overlying bony plates. There 
are no teeth, but the jaws are sharp-edged and cov- 
ered with horny sheaths. 'I’he eyes are furnished 
with two lids and a nictitating membrane, as in 
birds. Respiration is regarded as being accomplished 
by swallowing air. Agassiz divides the Testudinata 
into the two sub-orders, viz. : Amy doe, comprising 
the Land and Fresh-water Turtles, with retractile 
feet that may be used for walking; and Ghelonii, 
the Sea Turtles, with flipper-like feet, chiefly used 
for swimming. 
Family— TBSTUDINIDtE. 
'J’he Land 'I’ortoises. 
About twenty species of Land 'I’ortoises are 
known. 'I’hey are herbivorous, entirely confined to 
the land, and inhabit the warmer parts of both 
continents. 
THE GOPHER [Testudo Carolina). — 'This is genus 
Xerobates of Agassiz, and is the common burrowing 
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