INTRODUCTION. XIX 



distinct species, having found their way to our coasts, one 

 of them probably from the Mediterranean, and the other 

 from the American shores across the Atlantic. The former 

 is the Coriaceous Turtle, Spargis Coriacea, called by 

 Merrem by the specific name of Mercurialis, on account of 

 its having been in ancient times dedicated to Mercury, by 

 whom its shell was believed to have been employed in the 

 construction of the lyre. Of this species two specimens 

 are recorded by Borlase in his History of Cornwall, as 

 having been caught in the mackerel nets off that coast in 

 July 1756, the detail of which is given in the description 

 of the species. 



I have been induced to enter thus at large into the his- 

 tory of this tribe of reptiles, because, although we do not 

 possess any British species, there is every reason to believe 

 that several of the fresh -water species, both of Europe and 

 North America, might be naturalized in the southern parts 

 of England. The Terrapene Europaa, the common lacus- 

 trine Tortoise of the Continent, is found in Portugal, Spain, 

 Italy, and Greece, in France, and even in Prussia. These 

 Tortoises are eaten by the inhabitants of all the countries 

 in which they are found ; and as they live principally upon 

 small fish, the air-bags of which they reject, it is said that 

 the people are wont to judge of the quantity of Tortoises to 

 be found in a lake or pond, by the number of air-bags 

 which are seen swimming on the surface of the water. I 

 once placed in a small pond, in which were some of these 

 fresh- water Tortoises, six small living fish; and on the 

 following morning I found the air-bags of five of them 

 floating on the surface of the water, and the sixth fish still 

 alive. In some parts they are fed upon grains, and on 

 other nourishing food, and fattened for the table. There 

 are also several American species of Emys, or fresh- water 



