TERRAPENE CLAUSA. 
Testee ossece mensura. 
Var. a. 
une. lin. 
Longitudo dorsi .5 5 
Latitudo ejusdem. 4 1 
Longitudo sterni. 5 3 
Altitudo. 2 3 
Var |3. 
ur.c. lin. 
4 6 
4 0 
4 6 
2 3 
There is perhaps scarcely another species of Tortoise so liable to variation 
as this, whether in colour, in marking, or in form. From the comparison of 
only a few specimens, I some years ago described three of the most remark¬ 
able varieties as distinct species; but the possession of numerous individuals, 
several of which I have had the opportunity of observing whilst alive, has 
enabled me to ascertain that they all belong to one species. The common, 
and, as it may be termed, normal form is intermediate between the two 
extremes, which I then termed respectively nebulosa and maculata. 
The shell is ovate, somewhat broader behind, and considerably elevated; 
more so, in proportion, than any other species of the genus, and, consequently, 
than any other of the family of the Emydidce : the vertebral plates have an 
obtuse longitudinal carina; the dorsal ones are somewhat convex and rounded; 
the margin is re volute, particularly over the thighs. The scuta are slightly 
sulcated, and of a dark brown or blackish colour, with large yellow spots and 
splotches, which assume somewhat of a radiating and circular direction around 
the areolae, though not in any very marked degree. The sternum is in some 
specimens wholly yellow, excepting a few black or brown spots; in others it 
is beautifully mottled or clouded with black and yellow, pretty equally dis¬ 
tributed ; and in others, as in that from which the present figure is taken, it is 
almost wholly of a rich blackish brown colour. The margin of the sternum is 
very entire, and closes the shell accurately when the lobes are raised. The skin 
of the animal is marked with similar colours to those of the shell, the yellow 
predominating in some individuals, and the black in others. In one specimen 
in my possession, the whole of the lateral and under part of the head and neck 
