1 6 PRESIDENT'S ADDRESS. 



by the union of the ribs to each other at their base only. The 

 exo-skeleton is covered by a leathery skin. They are carnivorous 

 and inhabit fresh-water, and for the purpose of swimming the feet 

 are webbed. The carapace as well as the plastron are destitute 

 to a great extent of a bony support. The ribs, which are 

 cartilaginous, do not reach to the marginal plates. The neck, 

 tail, and ribs are furnished with scales. A good example of the 

 family is the Soft-shelled Turtle Trionyx ferox of the Southern 

 United States. 



Chelydridae Body covered with epidermal plates, head and 

 limbs not retractile, amphibious and carnivorous. This family 

 is found only in North and part of South America. The Alligator 

 terrapine (Chelydra) and the Larger Snapper (Macroclemmys) are 

 the most worthy of notice. If all the genera provisionally 

 assigned to this family are rightly referred, it will be the oldest 

 representative of the Order Chelonia. 



Emydidae The Terrapines, Pond Tortoises, and River Tortoises. 

 These are amphibious, living in ponds, marshes, and slow 

 streams. They can be easily distinguished from the Testudinidae 

 (Land Tortoises) as will be apparent in the diagnosis further on. 

 Several genera appear to live as much on the land as in the 

 water; their webbed-feet show aquatic habits. They frequent 

 the neighbourhood of fresh-water in nearly all the temperate 

 and tropical regions. The depressed carapace distinguishes it 

 from that of the Land-Tortoise, which is very convex. The 

 carapace of the Emydidce is intermediate between that of the 

 Chelonidob and Testudinidce, this is also the case with regard to the 

 limbs. 



Testudinidae Land-Tortoises. These have a solid convex cara- 

 pace, into which the head, limbs, and tail can be completely 

 retracted. Their habits are essentially terrestrial. A familiar 

 species, Testudo graeca, inhabits the countries which border on the 

 shores of the Mediterranean and is often imported into this 

 country. Several species of gigantic Tortoises are found in the 

 Galapagos Islands. Another gigantic species is found in Aldabra 

 Island, lying to the N.E. of Madagascar, attaining the length 



