viil INTRODUCTION. 



There has been some difficulty in deciding on the number of 

 specimens which should bo introduced into tho Catalogue, since the 

 Museum contains such vast quantities of the remains of some of 

 the commoner species that the introduction of the whole would be 

 utterly useless. In such instances the principle of introducing 

 nearly all the specimens displayed to the public in the cases of the 

 Mammalian Gallery has been adopted, together with such speci- 

 mens in the drawers as are of interest, either from their intrinsic 

 characters or on distributional grounds. 



As far as possible references are given to all works in which 

 individual specimens have been either described or figured. In 

 the case of figured specimens the word (-?%/.) is placed below 

 the number of the specimen. The specimens are referred to in this 

 Catalogue by their Register numbers. In the majority of cases 

 these numbers are written on oval yellow labels attached to the 

 specimens, the more recent acquisitions being ranged under the 

 letter M. In the case of some of the specimens which have been 

 longest in the collection the numbers are written on oblong white 

 labels, these numbers referring to a separate volume known as the 

 " Old Catalogue." Such specimens are entered with the affix O.C. 

 to their numbers. 



In the present state of science it is almost impossible to render 

 mammalian genera of equivalent value,, since some writers regard 

 extremely minute differences as of generic value, while others 

 (among whom is the present writer) use generic terms in a wider 

 sense. Thus, among the Carnivora, the genera Hyaena, Viverra, and 

 Cynodictis, as these terms are employed below, are examples of 

 generic terms used in the latter sense ; while some of the other 

 genera of the Viverridce are founded on very small differences 1 . In 

 cases of imperfectly known forms, or those whose existing allies 

 belong to groups very difficult to distinguish merely by those cha- 

 racters available in the case of fossils, the generic terms employed 

 by contemporary writers are very generally retained. 



In enumerating the teeth of the typical heterodont eutherian 

 Mammals, each tooth of the cheek-series is referred to its proper 

 position in the complete series, the first premolar always meaning 

 the first tooth in the typical series of four, and so with the succeed- 

 ing teeth. 



1 Thus, as far as can be judged from the mandible, it seems very doubtful 

 whether Palaoprionodon can be distinguished from Prionodon. 



