Fig. 2. Heads of American Alligator and American Crocodile; Alligator on Left. (After Ditmars.)
(Reproduced by Permission of Sturgis & Walton Co.)
The distribution of individual forms will be mentioned again when they are discussed in detail.
Alligator Mississippiensis
Since this animal, generally known as the American or the Florida alligator (formerly A. lucius), is the one upon which most of the facts of this book are based, it will be discussed first.
At this point it may be well to answer the question that is sure to be asked by someone early in any conversation upon the Crocodilia. The writer, and doubtless every other zoölogist, has been asked countless times, “What is the difference between an alligator and a crocodile?” As a matter of fact there is, perhaps, no absolute distinction between the two groups, but there are certain features that make it easy to distinguish, say, between the American alligator and the American crocodile.
The most striking difference is in the outline of the head; the alligator has a broad, rounded snout, while that of the crocodile is narrower and more pointed ([Fig. 2]). Again, in the crocodile the fourth tooth from the front projects slightly outwards and fits into a notch in the side of the upper jaw, while in the alligator (also in the caiman) the corresponding tooth on each side fits into a socket in the upper jaw and hence is hidden, except in some old animals with very long teeth, in which it may pierce the upper jaw and show from above. According to Ditmars, the crocodile has, as a rule, larger and more exposed teeth than the alligator. Finally, as will be brought out later, the crocodile is usually more quick and active, and also more vicious, than the alligator.
Very young alligators are nearly black, with distinct, yellow cross bands; as they grow older these markings become less distinct until in maturity the animals are of a uniform gray or dirty black color.
Habitat.
The American alligator is found in the rivers and swamps of the Southern States, from the southern part of North Carolina to the Rio Grande, though Florida is usually thought of as being the region in which they particularly abound. Years ago, before the rifle of the ubiquitous tourist and so-called sportsman had gotten in its deadly work, the alligators were probably very abundant in the Southern States; but they have been so ruthlessly destroyed by native hunters for their skins, and by others for mere wanton sport, that one may travel, perhaps, for days along the rivers of the South without seeing a single ’gator.