1 8 PRESIDENT'S ADDRESS. 



White River, Dakota (Miocene). The Emydidae, Freshwater 

 Tortoises became very abundant and widely distributed. There 

 are about 70 species now living in Southern Europe, Asia, 

 and North and Central America. The oldest representative in 

 Europe is Emys bicarinata from the London Clay of the Isle of 

 Sheppey. During the succeeding Miocene Age the present types 

 of Trionychidae, Testudinidae, and Chelonidae began to prevail, 

 while the Pleurodira, Marsh Tortoises, CheknemydidoK, and 

 Dermatemydidae which are so abundant in the Eocene Age dis- 

 appeared. Land Tortoises were varied and abundant in the Upper 

 Eocene Beds of the East Indies. The gigantic Land-Tortoise, 

 Colossochelys, has been found in the Fresh-water Beds of the Sivilak 

 Hills of India. It measures from fifteen to twenty feet in length. 

 Nothing is known of the ancestry of the Chelonia. There is 

 no evidence of the Order in the Palaeozoic Age. From the 

 absence of any sternal evidence, coupled with an analogous 

 structure of the humerus, and the limbs of the Stegocephali from 

 the Coal Measures, it has been suggested that the line can be 

 traced through them, but on a closer examination it is considered 

 that it cannot be thus solved. 



Of the four Orders of existing Reptiles the Crocodiles are the 

 most restricted in their distribution. There are 25 well-defined 

 species, all confined to the tropical and sub-tropical regions of 

 the world. These comprise three distinct families, Gavials, 

 Crocodiles proper, and Alligators. The Gavials are exclusively 

 Old-world forms ; Alligators, New World. Crocodilia represent 

 the most ancient group ; their first appearance dates from the 

 Trias ; Stagonolepis, from the Elgin Sandstones of Scotland, and 

 Belodon from Wurtemburg, the United States, and India ; 

 Parasuchia from India. The succeeding Jurassic Age yields 

 a number of distinct genera and species, including Teleosaurus, 

 Steneosaurus, Dakosaurus, and Goniopholis. All have been found 

 in this county. Gavials are found associated with Crocodiles in 

 the Upper Cretaceous beds of Europe. The Alligator delayed 

 its appearance in Europe and America until the Eocene Age. 

 The various Crocodilian types show a gradual structural 



