CLASS REPTILIA 541 



severe wounds. The plastron is very small and offers little 

 protection for the body. Chelydra rossignonii is a native of 

 Mexico and Guatemala, differing only slightly from C. serpentina. 



The alligator snapping- turtle, Macrochelys lacertina (Fig. 444), 

 lives in the streams of the southeastern United States. It is the 

 largest North American turtle, attaining a weight of one hundred 

 and forty pounds and a length of shell of twenty-eight inches. 

 It has " a head as large as that of a bull-terrier and jaws that can 

 chop up an ordinary broom handle," and a bad temper as well. 

 The flesh of the snapping-turtle is a regular article of food in 

 certain localities. 



Family KiNOSTERNiDiE. — Musk- and Mud-turtles. — These 

 are all confined to America. There are three species of musk- 

 turtles belonging to the genus Aromochelys, and eleven species 

 of mud-turtles of the genus Kinosternon. 



The common musk-turtle, Aromochelys odoratus, is an inhabit- 

 ant of the muddy streams of the eastern United States. It has 

 a carapace three or four inches long, a large head, and broadly 

 webbed feet. It is voracious and carnivorous. The disagree- 

 able odor it emits when captured has given it its name. 



The common mud-turtle, Kinosternon pennsylvanicum, shares 

 the habitat of the musk-turtle, and resembles the latter in size 

 and in habits. 



Family Testudinid^e. — Turtles, Terrapins, and Tor- 

 toises. — There are twenty-two genera and about one hundred 

 and ten species in this family. Space will permit a brief dis- 

 cussion of only six or eight of these. 



The painted terrapin, Chrysemys picta (Fig. 445), inhabits 

 the ponds and sluggish rivers of eastern North America. It 

 loves to sun itself upon a log or protruding rock, from which it 

 slides off into the water when disturbed. It feeds on aquatic 

 insects, tadpoles, fishes, and water-plants. The shells of the 

 painted terrapin are beautifully colored and are often carefully 

 cleaned and then varnished, in which condition they make very 

 pretty ornaments. 



