PREFACE. 
Tue collection of Tortoises and Crocodiles in the British Museum 
was that part of the herpetological series to which the late Dr. Gray 
paid special and unremitted attention. Besides numerous papers 
which appeared in various periodicals, he prepared the following 
Catalogues for publication by the Trustees :— 
ile 
to 
Ou 
Catalogue of Tortoises, Crocodiles, and Amphisbeenians. 1844. 
12° (pages 80). 
Catalogue of Shield Reptiles. Part I. estudinata. 1855. 
4° (pages 79, with 50 plates). Part IJ. Emydosaurians, 
Rhynchocephalia, and Amphisbeenians. 1872. 4° (pages 41, 
with woodcuts). 
. Supplement to the Catalogue of Shield Reptiles. Part I. 
Testudinata, with figures of the skulls of 36 genera. 1870. 
4° (pages x and 120). 
Appendix to the Catalogue of Shield Reptiles. Part I. Testu- 
dinata. 1872. 4° (pages 28). 
. Hand-List of the Specimens of Shield Reptiles. 1873. 8° 
(pages iv and 124), 
The collections made during the ‘Transit of Venus Expedition 
and the opportune visits, in the year 1875, of British vessels to the 
Galapagos Islands furnished unequalled materials for the thorough 
examination of a group of Tortoises which previously had not been 
well understood. This examination was undertaken by myself, and 
the results were published by the Trustees in 
6, The Gigantic Land-Tortoises (Living and Extinct). 1877. 
4° (pages iv and 96, with 54 plates), 
