irds of the United States in Number VI.

ENDURANCE TEST, OR HOW CLEAR GRIT WON THE DAY.

THE REPTILES OF THE UNITED STATES.

The reptiles are a class of vertebrate animals. By vertebrate animals is
meant those having a backbone. Reptiles are cold-blooded animals having
scaly skins, and breathing by lungs and not by gills as do the fish.
Strange as it may seem they are related to the birds. In prehistoric
times they were of enormous size and many of them were capable of
flying. Fossil forms of reptiles are very numerous and scientists have
given these fossil forms such sonorous names as Dinosaurs, Ichthyosaurs,
Plesiosaurs and Pterosaurs. These names are made up of Greek words
meaning terrible lizards, fish lizards, near lizards and winged lizards.

The class of reptiles is made up of five orders:

Sphenodons;
Lacertilia;
Ophidia;
Chelonia;
Crocodilia.

Of the Sphenodons, there is but one living representative. Its home is
in New Zealand. Zoologists tell us that this reptile is more closely
related to its fossil cousins than any other now in existence. Since we
are considering only those reptiles which an American boy may find
living in their natural haunts in his home land, discussion of the
Sphenodon is out of place in this article. We recommend, however, that
you read up about this curious creature that links the gigantic
prehistoric lizards with the little creatures of to-day's world.

[Illustration: PTEROSAURS.]

THE LIZARDS

THE LACERTILIA OR LIZARDS.

[Illustration: LIZARDS.
1. ZEBRA-TAILED LIZARD.
2. PACIFIC SWIFT.
3. COLLARED LIZARD.
4. WHITE-BELLIED SWIFT.
5. COMMON SWIFT OR FENCE LIZARD.]

Lizards differ from snakes in that the right and left halves of the
lower jaw are joined together by bone instead of elastic ligament and in
that they have legs and eyelids. They are found in the warmer climates.
Most of them live on insects, but some types as, for instance, the
Iguanas, live entirely on vegetable matter, while others prey on birds,
mice, frogs, etc.

THE GECKOS.

The Geckos form a large sub-order of lizards. Their chief characteristic
is their adhesive toes, which enable them to cling to and run on
smoothest surfaces even when upside down. They do not like the hot
sunlight and largely feed at twilight and at night. The Reef Gecko is
found in Florida; the Warty Gecko, so called on account of the rows of
large wart-like scales on its