THE SHELL OF A TORTOISE. 
The shell of a Tortoise is here shown with (on the right-hand side) and without (on the left-hand side) its skin-covering. It should be noticed that the joins in the horny skin do 
not correspond with the joins in the bony plate, and this points to an entirely separate growth of these two parts of the Tortoise’s shell, The grooves made by the joins in the skin 
show up as white grooves on the shell-bone. 
