EMYS CONCENTRICA.
nigro punctati. Testa ovalis vel subpentagono-ovata, subconvexa, interruptè carinata,
margine ferè integro, vel posticè crennlato, ad latera revoluto, anticè rotondato, et
levitèr emarginato. Scuta dorsalia glabra, concentricè sulcata, fusco-viridescentia,
nigro concentricè zouata : vertebralia obtusè carinata, in junioribus quasi tuberculata ;
primum pentagonuin ; secundum, tertium et quartum hexagona ; quintum irregula-
riter hexagonum, interdùm subpentagonum, margine posteriore latum, rotundatum :
costalia plana, declivia, primum quadrilaterale, figurse irregularis, margine superiore
angustiore, inferiore lato, rotondato ; secundum et tertium pentagono-quadrata,
angulis inferioribus rectis ; quartum rhomboideum, parvum : marginalia quadrata,
lateralia subrevoluta : scutum m ela le quadratoni, latum. Sternum latum, anticè sub-
truncatum, posticè emarginatum, flavescens, scutis singulis lineis et maculis fuscis
concentricè notatis : scuta jugalìa triangularía : kumeralia quadrilatera, introrsùtn
angustata : pectoralia oblongè quadrata, extrorsùm profundé sinuata : abdominalia
reliquis majora, quadrata : femoralia magna, trapezoides : analta rhomboidea.
Vár. a. scuta dorsalia habet omninò nigra, profundé sulcata, margine toto revoluto ;
et sternum pallidè fuscum, plagis subradiantibus. In Var. /3. (Tab. è.) scutum verticale,
collum, pedes, cauda atque testa nigri sunt. In Var. y. (Tab. c.) caput, collum,
pedes et cutis tota, pallidè virides, maculis, lineis et punctis nigris notati. In Var. S.
testa rufescens, zonis fuscis ; et sternum pallidè castaneum. In Var. s. testa unicolor
est, sordidè olivácea, sulcis scutorum obsoletis. •
In junioribus testa oblongè subpentagona, cariná vertebrali altiore, abrupté interrupts,
et sulcis scutorum profundioribus. ' In pullis testa suprà pallidè fusca, sternum
albidum, nigro minutissime punctatum.
Scutis dorsalibus amotis, testa ossea colorem flavum exhibet, zonis claré nigris.
Testa: ossea: mensura.
une. lio.
Longitudo d o r s i 8 5
L a t i tu d o ................................................................ 6 2
Longitudo sterni ..................... 7 5 .
Altitudo ..................................................... 3 2
This species appears to have received the name of concentrica from Dr.
Shaw, in the same year in which Latreille and Daudin applied to it that of
EMYS CONCENTRICA.
centrata. I have retained the denotnination of our English naturalist, sanctioned
as it is already by Mr. Gray in his Synopsis. The appellation “ Tortue
a li'gnes concentriques,” under which Bose described it, is as well rendered by
one as by the other of the Latin specific names above mentioned. Its identity
with Testudo palustris of Gmelin is too doubtful to authorize the application
of that term, though we have the authority of SchoepfF, of Leconte, and
of the Prince of Musignano in its favour.
This Tortoise is far from uninteresting, whether regarded as to its zoological
characters, its remarkable and numerous varieties, or its excellence as a nutritive
and delicious article of food. The .concentric furrows and coloured markings
of its plates at once distinguish it from all other species; but its characters
vary so much, not only in different specimens, but even in the same individual
at different periods of life, that I think it will not be destitute of utility to
notice some of the most remarkable of these variations.
When the young one first leaves the . .egg, it is of a light brown colour,
without concentric lines, each vertebral plate having a rounded tubercle,
which forms the centre of its future carina. At this period the head and the
skin of the neck and limbs are uniformly browh, without any of the spots
which characterize the older specimens; and the sternum is of a brownish
white colour, dotted over the greater part of its surface with minute points of
brown or blackish. When about half grown the concentric furrows are very
deep and sharp, the colour generally deep brown or black, and the carina on
each vertebra] plate high and tubercular. As it advances in age and size, the
carina is less prominent, the sulci become softened, and the plates, less deeply
coloured and more transparent, exhibit the dark concentric zones by which
the species is so well distinguished. On stripping off the plates, the pattern
is seen distinct and vivid on the surface of the bone beneath, consisting of
black zones strongly marked out upon a yellow ground. It was from a specimen
in this state that Shaw’s figure in the General Zoology was taken,
though he was ignorant of the cause of this peculiar appearance.
I have not thought it necessary to distinguish every minute variation of
colour which we see assumed by this very variable species. I have, however,
endeavoured to characterize the most striking and remarkable varieties. The