The alligator. Alligator mississippiensis (Daudin), has a broad rounded muzzle which at once distinguishes it from the crocodile with its narrow pointed head. The alligator of the Western Hemisphere (there is a single species in China also) inhabits the rivers and swamps of northern South Carolina, of Georgia and Florida, and westward through Mississippi and Louisiana to the Rio Grande in Texas. The teeth in the upper jaw overlap more or less those below; the large tooth fourth from the front on the lower jaw fits into a deep pit in the jaw above.

Title: The American Museum journal
Year: c1900-(1918) (c190s)
Authors: American Museum of Natural History
Subjects: Natural history
Date 1918
Source book page: https://archive.org/stream/americanmuseumjo18amer/#page/n522/mode/1up
Source: https://commons.wikimedia.org/wiki/File:The_American_Museum_journal_(c1900-(1918))_(17973766918).jpg

The American alligator or gator (Alligator mississippiensis) is a large crocodilian reptile endemic to the southeastern United States. It is one of two living species in the genus Alligator within the family Alligatoridae.