Vill INTRODUCTION. 
There has been some difficulty in deciding on the number of 
specimens which should be introduced into the 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 (/fig.) 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 0.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 Hyena, 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 Vivermde are founded on very small differences*. 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 Palgoprionodon can be distinguished from Prionodon. 
