VOL. XIV. (1) FOREST BED—PALHONTOLOGY 43 
1. MAMMALIA. 
Microtus agrestis (Linn.) (Field Vole). A right anterior 
lower cheek tooth, possessing five inner and four 
outer angles, thus agreeing in pattern and also in size 
with the corresponding tooth in the Field Vole, un- 
doubtedly represents this species. The anterior prism of 
this tooth has its inner and outer extremities rather more 
protuberant than is the case in most recent examples, 
thus giving rise to a little accessory angle on each side. 
I have seen, however, several examples of this in recent 
molars of J. agrestis that have come under my notice 
from time to time. 
This species is known from several other British Post- 
Pliocene deposits. 
Microtus glareolus, Schreb. (Red Bank Vole). A first 
lower molar of the right side exhibits four inner and four 
outer angles, and is referred to AZ. glareolus. The form 
of the anterior portion of the tooth agrees very closely 
with fig. 180 of Blasius (“Saugethiere Deutschslands,” 
p- 338), in which the anterior or fifth inner angle is 
absorbed in the confluency of the prism just behind it. 
The specimen indicates a young individual, the only sign 
of the fangs which are developed in the adult being a 
slight constriction of the basal portion of the crown. In 
this series there is also a right second lower molar with 
three inner and three outer angles. The specimen like- 
wise belonged to a young individual, the bases of the 
pulp cavities being only partially closed. M/Z. glareolus 
has been found in the Norfolk Forest Bed, and in several 
English Pleistocene deposits. 
Mus sylvaticus, Linn. (Wood Mouse). A left ramus 
preserved in this collection presents the following 
characters :—The incisor is intact, but the molar teeth are 
unfortunately missing. The alveoli of the latter are 
