UBSUS ARCTOS. 81 



space in the Fen Bear contains the sockets of two small 

 spurious molars, each with a simple fang (given in outline in 

 jig. 22), but there is no trace of these in the Cave Bear, save 

 in very rare exceptions ; and this difference cannot be the 

 effect of age, because the lower jaw of the Fen Bear, which 

 has the grinders moderately worn by mastication, is here 

 compared with the jaw of a young and small Ursus speleeus-, 

 in which the tubercles of the grinding teeth are all entire. 



The Fen Bear resembles the Ursus priscus in so far as the 

 latter retains thj3 first false molar, but differs in possessing 

 the second, which is wanting in a younger specimen of the 

 Ursus priscus ; it differs also in the greater extent of the 

 interspace between the canine and the third false molar ; 

 and, more importantly, in the form of that tooth, which 

 in the Ursus priscus presents a second cusp on the inner 

 side, and a little behind the first, which cusp is wholly 

 wanting in the corresponding tooth of the Fen Bear. The 

 ramus of the jaw is deeper, and the slope of the symphysis 

 is more gradual. 



These characters are illustrated in the comparative views 

 of the dentition of the lower jaw of Ursus Arctos, U. pris- 

 cus, and U. spel<zus,fig. 35. 



In all the particulars in which the Fen Bear differs 

 from the two extinct species above cited, from the caverns, 

 it agrees with the existing Ursus Arctos, and especially 

 with the darker variety of Europe, from which it does not 

 appear to differ in any well-marked specific character. The 

 Grisly Bear of North America agrees with the Cave Bear 

 (Ursus spelaus), and differs from the Ursus Arctos and the 

 present British fossil representative of that species in the 

 absence of the first two false molars and in the more com- 

 plicated crown of the third false molar. 



