INTRODUCTION. 



The present Catalogue, like that of the Possil Mammalia, is exclu- 

 sively confined to species and genera represented in the Collection 

 of the Museum ; although in a few instances the names of certain 

 larger groups, which are at present desiderata, have been introduced 

 in order to render the general scheme of classification less imperfect 

 than would otherwise be the case. Unlike, however, the earlier 

 parts of the e Catalogue of Fossil Mammalia,' the present work is 

 descriptive throughout — this addition to its bulk being almost 

 imperative in order to justify the specific and generic reference of 

 many of the individual specimens. 



In order to avoid adding one more to the numerous schemes of 

 classification which have been proposed for the Eeptilia, it has been 

 thought advisable to take one of those already published, and to 

 adhere in the main to the arrangement thus adopted. The classifi- 

 cation selected as a guide was recently published by Dr. George 

 Baur l , of Yale College, and is a modification of a scheme previously 

 proposed by Prof. E. D. Cope 2 , of Philadelphia. In this arrange- 

 ment the orders of the Eeptilia are divided into several groups or 

 branches, for which the names proposed by Prof, Cope have been 

 retained ; although it has been thought better to use them in an 

 adjectival form rather than to make them into definite subclasses. 

 Dr. Baur's scheme differs from that of Prof. Cope by the removal of 

 the Anomodontia (Theromorpha) from the branch which includes 

 the Dinosauria, Crocodilia, and Ornithosauria ; and the transference 

 of the Bhynchocephalia from the neighbourhood of the Chelonia and 

 Sauropterygia to that of the true Lizards- — the latter change being 

 in harmony with the views recently expressed by Prof. Huxley 3 . 

 The Ichthyopterygia, moreover, instead of being placed as a group 

 totally distinct from all other Eeptiles, are regarded by Dr. Baur as 

 closely related to the Lizards and Ehynchocephalians — a view which 



1 Sitz. ges. Morph. Miinchen, vol. iii. pp. 46-74 (1887) ; also Jouru. Morphol. 

 vol. i. pp. 93-104 (1887); and Biol. Centralblatt, vol. vii. pp. 481-493 (1887). 



2 Ainer. Nat. vol. xix. pp. 245, 246 (1885). 



3 Quart. Journ. Geol. Soc. vol. xliii. pp. 691, 692 (1887). 



