﻿UESUS. 



31 



brown than in the grizzly bear, but this difference does not always hold, and skulls 

 sometimes show a remarkable amount of variation in this respect. 



Dr. H. Woodward 1 quotes Dupont as stating that skulls of brown and grizzly 

 bears may be distinguished by the fact that U. arctos has only the last small 

 upper premolar (i. e. pm. 3), while the grizzly has also pm. 1 . Whether this 

 were a true distinction could only be determined by reference to recent skulls, 

 and in these it emphatically does not hold. The following table shows the distri- 

 bution of the small premolar teeth in a number of bears' skulls, recent and fossil, 

 and it will be seen that all the recent skulls of the brown bear referred to, 

 show pm. 1 in addition to pm. 3 ; in one case also pm. 2 is present. 



(8) Table showing Development op Small Peemolaes and of Cusps on pm. 4 in Beaks 

 of the arctos Type. 





pm. 1. 



pm. 2. 



pm. 3. 



pm. 1. 



pm. 2. 



pm. 3. 



Cusps on 

 pm. 4. 



Cranium and Mandible. 



77. arctos, Kamtchatka, No. 91.12.18.13 (Brit. 



Mus.) 



77. arctos, Jesso, No. 96.4.27.1 (Brit. Mus.) 



77. arctos var. piscator, N.W. Asia, No. 93.9.10.1 



(Brit. Mus.) 

 77. arctos, No. 61.4.1.3 (Brit. Mus.) 



77. horribilis, No. 78.6.18.1 (Brit. Mus.) 



+ 



+ 

 4- 



Alv. one 

 side 



+ 



+ 

 + 



+ 

 Alv. 

 Alv. 

 Alv. 



+ 



Alv. 

 Alv. 



+ 



Alv. 



+ 

 Alv. 



+ 

 + 



Alv. 

 One side 



Alv. 

 Alv. 

 Alv. 



+ 

 + 



+ 



+ 



+ 



+ 

 + 



Alv. 



+ 

 + 



Alv. 

 + rt. 

 side 



Alv. 



One side 



Alv. rt. 



side 



Alv. 

 Alv. 



No cusps. 



1, 2, 3. 



2 (small). 



No cusps. 



2 



No cusps. 

 No cusps. 



No cusps. 

 No cusps. 



1 



No cusps. 



2 (small). 



1,3. 



Tooth 



wanting. 





77. horribilis var. horrixus, No. 67.2.23.3 

 (Brit. Mus.) 



77. horribilis, Muggendorf (Brit. Mus.) 



77. horribilis, 1 Ballynamore (Brit. Mus.) 



77. horribilis, Ballyniahon (Leeds, cast Brit. 



Mus.) 

 77. arctos, 1 Bourn, Lincoln (Mus. Pract. Geol.) 





77. arctos 1 (labelled 77. spelseus), Crayford, 

 No. M. 5041 (Brit. Mus.) 



Mandible. 



77. arctos, Manea fen (Pig. Owen, p. 106, fig. 



35a), No. M.231 (Brit. Mus.) 

 77. arctos, St. David's (Brit. Mus.) 



77. arctos, Grower, No. 859 (Coll. Surgeons Mus.) 

 77. horribilis, Grays, No. 22030 (Brit. Mus.) ... 

 77. horribilis, Deborah Den, No. 40949 (Brit. 

 Mus.) 



1 



NOTE.— The position of the small cusps to which the figures 1, 2, 3 in the last column of the above table 

 refer, is indicated in Fig. 6 on PI. VI. In the other columns a + indicates that the tooth is present ; if the tooth 

 has been lost, but its socket is present, " Alv." is written. 



1 Figured. 



Geol. Mag.,' viii, 1871, p. 197. 



