182 POPULAR OFFICIAL GUIDE. 
by side in our Reptile House afford striking examples of 
protective coloration. The Diamond-Back Rattler of Florida 
and the South is yellow, brown, and black, to match the 
checkers of sunbeam and shadow that fall upon the sands 
under the palmetto leaves. 
THE BATRACHIANS, OR AMPHIBIANS. 
Among the many wonders of Nature, none is more in- 
teresting than those forms which serve to connect the great 
groups of vertebrate animals, by bridging over what other- 
wise would seem like impassable chasms. 
Between the birds and the reptiles there is a fossil bird, 
called the Archeopteryx, with a long, vertebrated, lizard- 
like tail, which is covered with feathers, and the Hesperornis, 
a water bird with teeth, but no wings, which inhabited the 
shores of the great western lake which has already yielded 
to American paleontologists a great number of most remark- 
able fossil forms. 
Between the reptiles and the fishes, stretches a wonderful 
chain of living links by which those two Classes of verte- 
brates are so closely and unbrokenly united, and by such 
an array of forms, that they constitute an independent Class, 
the Batrachia, or Amphibia. In the transition from water 
to land, from fins and gills to legs and lungs, Nature has 
made some strange combinations. In some instances the 
fins, legs, lungs and gills have become so mixed that several 
notable misfits have resulted, and in some cases we see gills 
and legs going together, while in other lungs and fins are 
associated. 
The Reptile House contains about two dozen species of 
Amphibians, and it is reasonaly certain that this number 
will be maintained and increased. They are to be found 
in small aquarium cases, ranged along the south side and 
eastern end of the Main Hall. 
The Bullfrog, (Rana catcsbiana), is a fair representative 
of the Batrachians which stand nearest to the true land- 
going reptiles. During the early stages of its existence it is 
in turn, a fin-tailed tadpole with no legs, a short-tailed tad- 
pole with a pair of front legs, a shorter-tailed tadpole with 
four legs, and finally a fully-developed, land-going frog 
with a voice like a small bull, and no tail whatever. Of the 
genus Rana, there are five species in the eastern United 
States, several of which inhabit the Zoological Park. 
