34t> CHELONIA CHAP. 



This large family is cosmopolitan, with the exception of the 

 Australian and the adjoining Austro-Malavan countries. It 

 contains genera which form a continuous gradation between 

 absolutely terrestrial and thoroughly aquatic tortoises ; and many 

 are truly amphibious. As a general rule the typically terrestrial 

 kinds have a more curved or arched shell, the digits are short, 

 the eggs are more oval or round, and they are chiefly herljivorous ; 

 the essentially aquatic kinds have a flatter or depressed shell, 

 webbed feet, witli longer, often slender claws, the eggs are more 

 cylindrical, and they live on animal diet. About 20 genera, 

 with more than 110 species, are recognised by Boulenger, but 

 their essential characters are nearly all internal, and therefore 

 of no avail for the determination of live or entire specimens. 



Chrysemys. — One of the most t}pical and widely distributed 

 genera of American Terrapins or water-tortoises. The carapace 

 is flat ; tlie plastron is quite immovable, with a strongly developed 

 bridge. Feet well webbed. Tail short. Skull with a broad, 

 complete, lateral, temporal arch. About one dozen species, mostly 

 in the eastern half of the United States, Init the whole genus 

 ranges from Canada to Artjentina. 



Most of the young Chrysemys are very pretty, the ground-colour 

 of the upper shields being green, variegated with yellowish-brown 

 or blackisli markings, which often form exquisitely delicate 

 patterns, either concentrical {Cli. concinna, Ch. ruhriventris), or 

 more longitudinal {Ch. eJeyrois), or apparently quite irregular. 

 The ground-colour of the plastron is yellow, but* the various 

 species are best distinguished, at least in very young individuals, 

 by the arrangement of the dark brown spots and patches. There 

 are, for instance, several pairs of bold lateral and several median 

 patches in Ch. riihriventris ; five pairs of ocellated spots in Cli. 

 eleijans ; only small median patches, where four plastral shields 

 meet, in Ch. roncLiinct ; wliile the plastron of Cli. picta is uniformly 

 yellow. 



These water-tortoises are very lively and shy, most so. perhaps 

 Ch. 2)icta, which is very quick and active. The food varies, often 

 according to individual fancy. Most of them eat fish. Ch. picta 

 is partial to insects, but it also takes worms. Some of my 

 specimens refused meat for a long time, l»ut ultimately they 

 became so fond of it and of worms, that they came out of the 

 pond to take the food from the fingers ; those in the Zoological 



