466 CHELONIANS. 



less than four inches in length. It is common in marshes and 

 ditches from Maine to Florida. The carapace is gibbous or ob- 

 long, of a brownish color, with streaks of green. The color and 

 marking are, however, not easily detected, as the animal is usu- 

 ally covered with mud, and an agglutination of water plants. 

 It is sometimes called Mud Terrapin, and, on account of its dis- 

 agreeable odor, Stink-Pot, and other names equally savory. 



FOURTH FAMILY. Chelydroida, (Gr. xefodgog, cheludros, a 

 water-tortorse.) 



SNAPPING TURTLES. 



The body of these Tortoises is high in front and low behind, 

 the upper surface is "like a shed-roof falling backwards, curved 

 down on either stde, lowest about the middle, less and less to- 

 wards the ends." The carapace projects beyond the attached 

 surface of the body, except at the neck, where it is joined with 

 the plastron ; the latter is not movable, of a cross-like shape, and 

 covered with twelve plates. The head is very large and cov- 

 ered with small plates ; the upper mandible is hooked ; below 

 the under mandible are two small wattle-like excrescences. The 

 tail is extremely long, compressed and surmounted by a ridge 

 of strong scales, as in the crocodile. The limbs are very robust, 

 and the nails of the toes are strong, hooked and sharp. The 

 head, though of great size, can be withdrawn within the cara- 

 pace ; but not so the tail and limbs. " The animal lives mostly 

 in the water, but makes considerable passages over land. It does 

 not, like the Trionychida, remain burrowed in the soft muddy 

 bottom, but rather lies in wait for prey under shelving banks, or 

 among the reeds and rushes." 



This family is represented by the ALLIGATOR TORTOISE, or 

 SNAPPING TURTLE, to which naturalists have given various 

 names, among which are Chelonura, (Gr. chelone, tortoise ; oura, 

 a tail,) Serpentina, (Say ;) Gypochelys, (Gr. gups, a vulture ; 

 chelus, a tortoise.) Serpentina, (Agassiz.) Both internally and 

 externally, it exhibits an approach to the alligator, and perhaps 

 may be viewed as an intermediate link. When adult, it exceeds 

 ^ three feet in its total length. So great is the strength of its jaws 

 that a large one has been seen to bite off a piece of plank more 

 than an inch thick. It eats frogs, other aquatic reptiles, and 

 even fish ; it swims with celerity, and is prone to snap at every 

 thing coming near it. Woe to the unwary duck or other animal 

 that swims unguardedly within its reach. . The Alligator Tor- 

 toise is a native of Carolina and the warmer districts of North 



