420 CROCODILES AND ALLIGATORS. 
shell” of commerce, and is therefore a creature of great importance. The 
scales of the back are thirteen in number, and as they overlap each other 
for about one-third of their length, they are larger than in any other species 
where the edges only meet. In this species, too, the scales are thicker 
stronger, and more beautifully clouded than in any other Turtle. 
The uses to which this costly and beautiful substance are put are in- 
numerable. The most familiar form in which the tortoiseshell is presented 
to us is the comb, but it is 
also employed for knife 
handles, boxes, and many 
other articles of ornament 
or use. ; 
THE best known of all 
the Turtles is the celebrated 
GREEN TURTLE, so called 
from the green colour of its 
fat. 
This useful animal is 
found in the seas and on 
the shores of both conti- 
* nents, and is most plentiful 
about the Island of Ascen- 
sion and the Antilles, where 
it is subject to incessant 
persecution for the sake of 
GREEN TURTLE.—(Chelonia viridis.) its flesh. The shell of this 
reptile is of very little use, 
and of small value, but the flesh is remarkably ‘ich and well-flavoured, and 
the green fat has long enjoyed a world-wide and fully deserved reputation. 
The eggs of the Turtle are thought as great delicacies as its flesh. It is 
while the female Turtle is visiting the shore for the purpose of depositing her 
eggs that she is usually captured, as these sea-loving reptiles care little for 
the shore except for this purpose. 
CROCODILES AND ALLIGATORS. 
ACCORDING to the arrangement of the national collection in the British 
Museum, the link next to the tortoise tribe is formed of an important group 
of reptiles, containing the largest of the reptilian order, larger indeed than 
most present inhabitants of the earth. 
These great reptiles are divided, or rather fall natutally, into two families, 
namely, the Crocodiles and the Alligators. All the members of these 
families can be easily distinguished by the shape of their jaws and teeth, the 
lower canine teeth of the Crocodiles fitting into a zofch in the edge of the 
upper jaw, and those of the Alligators fitting into a gé¢ in the upper jaw. 
This peculiarity causes an obvious difference in the outline of the head, the 
muzzle of the Crocodiles being narrowed behind the nostrils. while that of 
the Alligators forms an unbroken line to the extremity. A glance therefore 
at the head will suffice to settle the family to which any species belongs. In 
the Crocodiles, moreover, the hind-legs are fringed behind with a series of 
compressed scales. 
THE most peculiar of these reptiles is the long-celebrated CROCODILE of 
Northern Africa, 
