PENSYLVANIAN TORTOISE 61 



up the shell. It is from this circumstance that 

 it appears to have been sometimes confounded 

 ~\vith the species just mentioned, though widely 

 differing in other particulars. The head, on the 

 parts surrounding the jaws and the eyes, is of a 

 reddish yellow colour: the upper part dusky, as 

 are also the neck, legs, and tail : the feet are 

 webbed, and have five toes on the fore, and four 

 on the hind feet : the tail is small, rather short, 

 and terminates in a callous or horny point, curv- 

 ing slightly downwards. It is a native of North 

 America, and is found in Pensylvania, &c. inha- 

 biting muddy waters, and is known by the name 

 of the Mud Tortoise. When living, it is said to 

 have a strong musky odour. 



VARIETIES. 



MR. SCHOEPF mentions a variety, in which the 

 under shell was not moveable, and imagines it to 



o 



constitute a sexual difference. 



In the British Museum, are specimens of about 

 the size figured by Edwards, one of which differs 

 very considerably from the rest in having a very 

 conspicuous carina or ridge down the back, ow- 

 ing to the sudden sloping of the sides : in other 

 particulars it resembles the rest. 



A much more remarkable variety (if it be not 

 rather a distinct species) occurs in the Leverian 

 Museum. This shell measures about four inches 

 and three quarters in length, and has every ap- 

 pearance of being full grown. Its colour is 



