TESTUDO CARBONARIA. 
Testa; ossea; mensura . 
Longitudo dorsi. 
Latitudo ad scutorum marginalium par quartum 
-sextum 
— : --nonum 
Altitudo testae. 
Longitudo sterni . 
ped. une. lin. 
1 0 5 
0 7 5 
0 6 7 
0 9 0 
0 5 6 
0 10 6 
Although the distinctions which exist between this species and T. tabulata 
are such as might strike even an unpractised erpetologist as sufficient at once 
to point them out as distinct, it was not until Spix examined them both, in 
every stage, in their native country, that they were properly discriminated; nor 
indeed had any attempt been offered at showing their distinctive characters, 
nor even a suggestion to that effect been made, by previous authors. Daudin 
has, in fact, described a specimen of this species as T. tabulata ; and Spix him¬ 
self, to whom the merit of distinguishing them belongs, has much diminished 
its value, by the total want of discrimination which he has evinced in forming- 
three new species from as many mere varieties of age and colour of T. tabulata. 
I had, it is true, long before separated, in my own cabinet, the specimens of 
T carbonaria from those of tabulata; but this had been the result of the very 
marked differences which are so obvious in the living animals, rather than from 
those essential characters in the form of the shell which, though less striking, 
are so constant as to constitute excellent specific distinctions. 
Mr. Gray has applied to the present species the specific name of Hercules 
given by Spix to the aged state of T. tabulata ; although, if there be one 
condition of that species more dissimilar than all others from the true carbonaria , 
it is this. The very figure on which Mr. Gray has founded his adoption of 
Spix’s name, contradicts in a most striking manner his own specific character, 
“ lateribus inflexis ; ” for in the Plate the sides are distinctly convex; whilst 
in the figure of carbonaria , in the same work, the characters are all sufficiently 
well expressed. 
The characters in which the present species differs from T. tabulata are 
