E. T. Newton — Hamster from the Norfolk Forest Bed. Ill 



form oblique trausverse ridges, wliicli are, however, interi'upted in tlie 

 middle by a deep depression, -which is in part due to wearing away by 

 the attrition of the lower grinders, and which runs from front to back 

 along the middle of the three teeth. The anterior molar has a distinct 

 cingulum running along the inner side of the crown, and a similar 

 cingulum, but much less distinct, is also to be seen on the second and 

 third molars. 



Cricetiis vulr/aria Bnntonenais, u.subsp. From tlie Norfolk Forest Bed at West 

 Runton. Grinding surfaces of three molars of right maxilla, enlarged six times. 

 The specimen is in the possession of A. C. Savin, Esq., of Cromer. 



A comparison of this little maxilla with a number of recent 

 specimens in the British IMuseum at South Kensington and in the 

 Museum of the Roj-al College of Surgeons, Lincolns Inn Fields,^ 

 leaves no doubt as to its generic identity with the common Hamster 

 Cricetus vulgaris { = frumentarms). The main characters of the teeth 

 are the same ; but in none of the recent specimens is the anterior 

 outer cusp of the first molar larger than the others, and there is no 

 outward expansion of this region which would correspond with 

 a larger anterior cusp. The teeth of the ' Forest Bed ' specimen 

 are likewise larger than those of any of the recent specimens examined, 

 in which the length of the series of three upper crowns varied from 

 7*4 to 7-7 mm. Dr. Nehring- in his paper on Pleistocene Hamsters 

 gives the extreme measurements of the three upper teeth in recent 

 Hamsters as 7-4 and 8-0 mm. 



The large size and difference in structure of these ' Forest Bed ' 

 teeth, as well as the age of the beds from which our fossil was obtained, 

 make it highly probable that it represents a form specifically distinct 



^ I am pleased to -have this opportunity of thanking the officers in charge at both 

 these institutions for the courteous assistance so kindly rendered on this as on many 

 other occasions. 



• - " Ueber pleistocaue Hamster-Reste aus Mittel- und Westeuropa " : Jahrb. k.k. 

 geol. Eeichsanst., 1893, Band xHii, Heft ii, p. 179. 



