98 URSID®. 
of the hind-foot (metatarsals and phalanges), by their size 
and general ursine characters, to belong to the Ursus 
spelaus, from different Cave localities in England: but none 
of these bones have presented any well-marked modification 
of form by which they might be distinguished, in addition 
to their size, from the corresponding bones in the smaller 
extinct and existing species of Bear. But the coicidence 
of such appreciable modifications m the femur, ulna, and 
humerus, of the great Cave Bear, with those in the form 
and proportions of the head, and in the form and the 
relative size of certain teeth, offer as good grounds for the 
specific distinction of the Ursus speleus as for that of the 
Ursus maritimus, or of any other existing species defined by 
Pallas and Cuvier, and admitted by the best modern zoolo- 
gists. 
The question which the Paleontologist ought to propose 
to himself in his first survey of the fossils of any particular 
district, is the value of the differential characters which 
such remains may present, as compared with those which 
distinguish the living species, according to the zoological 
systems and principles of the time being. It is true that 
the extent of the influence of external causes, operating 
through a vast series of ages, has not yet been determined ; 
but this only renders it the more imperative to take cog- 
nizance of all modifications in fossils which, according to 
present knowledge, cannot be so explained. 
To refuse to recognise such differences as have been 
pointed out in the skeleton of the great Cave Bear, because 
they may be accounted for by a hypothetical degeneration 
of the specific type, and thereupon to record the fossil 
species as the primeval state of the present Ursus 
Arctos, seems a voluntary abandonment of the most valuable 
