14 PBOCEEDIIfGS OF THE 



The Peesident's Anniveesaet Addeess. 



The subject which I have selected for my Address is one to which 

 I paid much attention some twenty years ago, which I have 

 never lost sight of since, and the study of which I intend to 

 resume, not only with much larger materials, but also with the 

 advantage of the labours of others who have opened up new 

 vistas, or thrown light into corners where I groped in the dark. 

 The subject is that Chelonian type which is generally known as 

 " Gigantic Land-Tortoises ; " which in Tertiary ages occupied a 

 wide range in the Northern Hemisphere, but is now reduced to 

 the fast expiring tenancy of a few oceanic islands. I trust I 

 shall be able to awaken your interest in this type. Although 

 long neglected, it should take its due position in the inquiry inta 

 certain great biological questions, quite apart from the smaller 

 problems which legitimately fall to the share of the specialist. 



In order to render the following remarks readily intelligible to 

 all, I may be permitted to recapitulate shortly the principal facts 

 of the history and distribution of these animals. They are 

 typical Land-Tortoises whose structure does not essentially difier 

 from that of our small European species : they are only gigantic 

 reproductions of the ordinary type, some of the living forms 

 attaining a weight of some 700 pounds, and a length of carapace 

 of 4 or 5 feet. Yet, even such giants are far surpassed in size 

 by some of the Tertiary species, notably those of the Sivalik 

 Hills. 



Large species of Testudo occur, among a host of smaller forms, 

 as far back as the Eocene, in North America * as well as Europef . 

 Their remains are more numerous in Miocene and Pliocene 

 formations. They have been found in various localities in 

 France and South Germany, in Malta, on the Lebanon, in the 

 Sivaliks ; and, in North America, in similar formations of 

 Nebraska and Wyoming J. Some of these fossils, so far as they 

 are known, approach very closely to the species of our time. 

 Even such a slight advance of specialization as distinguishes the 

 Testudo atlas of India, and which consists in the bifurcation of 

 tlie epiplastron, reappears, though in a modified form, in a 

 Mauritian tortoise recently described by Gadow. 



These Tertiary Tortoises have left no descendants on the 

 continents of the Old or New World : they were unable to survive 



* Hadrianus, Cope. 



t Lydekker, Cat. Foss. Eept. B. M. iii. p. 91. 



\ Tlie Chelonian remains hitherto discovered in South America are in too 

 fragmentary a condition to admit of useful comparison. So far as I know, 

 none are known from the African continent. 



