TESTUDO CARBONARIA.
Testce ossea mensura.
Longitudo d o r s i .....................................................
Latitudo ad scutorum marginalium par quartum
----------------------------- sextum
' ~ j . - -— , u ■ ■ ■ i —_ uonuui .
Altitudo te s ts e .........................................................
Longitudo sterni . . ..........................................
ped. unc. lin.
i 0 5
0 7 5
0 6 7
0 19 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 prqperly 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. tdbulata; and Spix'himself,
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
TESTUDO CARBONARIA.
striking and constant. The following parallel will exhibit the most important
of them.
In T . tabulata.
The general colour of the skin a lightish
olive.
Scales on the legs yellow.
Ground colour of the shell fuscous, in
old specimens brownish yellow, with yellow
areolae.
Tail extremely short.
Posterior sternal notch triangular, nearly
half as deep as it is broad.
In T . carbonaria.
The general colour dark olive, approaching
in parts to black.
Scales on the legs a deep bright red.
General colour of the shell a rich deep
black, with yellow areolae.
Tail moderately long.
Posterior sternal notch lunate, very broad
and shallow, the depth being less than one
fifth of the breadth.
In young specimens the shell is not contracted at the sides; but in older
ones the middle of the shell is narrower by about an inch than the anterior
part, and by nearly two inches and a half than the hinder part. The plates
also lose the sulci and become polished by age.
I have a shell of this species exhibiting a very remarkable variation in form,
in which the bones are exceedingly thick and heavy, and raised beneath each
plate, so as to give a considerable degree of elevation to each dorsal plate; the
areolae are truncated. (See the Plate B.)
The habits of this species resemble those of T. tabulata; but it inhabits a
more southern latitude, as I believe it is not found in any part of the United
States. It is very common in Brazil, Demerara, and the whole of Tropical
America, as well as in the island of Jamaica.
The egg is very similar to that of T. tabulata, but rather smaller, being an
oblate spheroid, of which the greater diameter is 1 inch 9 lines, and the less
1 inch 6 lines.