80 URSID &. 
the Ursus priscus with which it is compared, and to have 
attained that age when no difference could be expected to 
take place in the length of the interspaces of any of the 
teeth. In all the characters in which the upper jaw of the 
Fen Bear differs from that of the two species of Cave 
Bear with which it has been compared, it agrees with the 
Ursus Arctos. 
In regard to the two varieties of existing European Bear, 
brown and black, held by some to be distinct species, the 
entire skull in the Woodwardian Museum shows that the © 
most recent of the extinct British Bears, in its less convex 
forehead, and the greater length of the sagittal crest, re- 
sembled the Black Bear of Norway and Siberia, more than 
it did the Brown Bear of the Alps and Pyrenees. 
As it may aid in the subsequent attempt to elucidate the 
true specific characters of the extinct Cave Bears (Ursi 
speleus et priscus), as well as those of the existing Ursus 
Arctos, 1 shall add a few observations arising out of the 
comparison of the lower jaw of the Bear from the Manea 
Fen. The specimen, which is in the collection of Sir 
Philip Egerton, is the left ramus of the lower jaw. 
It equals in length the largest specimen of the lower jaw 
of the Ursus speleus, but differs from that species in the 
more simple form of the last premolar, or the fourth 
grinder, counting from behind forwards; for, whereas the 
Cave Bear has two distinct tubercles and a ridge deve- 
loped from the base of the principal cone of that tooth, in 
the present species there is only the principal cone, as in 
the Black, Brown, and White Bears. The Bear of the 
Fen also differs from the Ursus speleus in the shorter inter- 
space between the last described molar and the canine, 
even when its lower jaw is compared with the lower jaw 
of a Cave Bear of less dimensions. The preceding inter- 
