42 CHELONIAMYDAS. 



is probable enough, but with us all the Green Turtles that have ever fallen under my 

 observation appertained to one species, the Chclonia mydas; this animal however 

 varies much in shape at different epochs of life: it is broader in the young, and the 

 vertebral plates are then more extensive transversely, as in the Chelonia virgata. 

 They vary also exceedingly in colour, so that of hundreds that I have frequently 

 seen together scarcely two could be selected of precisely similar colours; some were 

 marked as above, others were darker; some with the shell radiated with dark or 

 with light brown, others had an oUve hue; while in the old animals a remarkable 

 tinge of green prevailed over the whole superior surface of the body; and some 

 young specimens I have seen marked with colours similar to the Chelonia imbri- 

 cata, and nearly as beautiful; so that colour alone, as in the Cistuda Carolina, is 

 not here sufficient to distinguish species. 



