EMYS CONCENTRICA. 
centrata. I have retained the denomination of our English naturalist, sanc¬ 
tioned as it is already by Mr. Gray in his Synopsis. The appellation “ Tortae 
a lignes concentriques ,” under which Bose described it, is as well rendered by 
one as by the other of the Latin specific names above mentioned. Its iden¬ 
tity with Testudo palustris of Gmelin is too doubtful to authorize the applica¬ 
tion 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 nutri¬ 
tive and delicious article of food. The concentric furrows and coloured mark¬ 
ings 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 brown, 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 spe¬ 
cimen 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 
