678 CASTORIDA—CASTOR 
British species is C. vetertor, Lankester, from the Red Crag of Suffolk 
(Pliocene). In this, certain of the enamel folds of the molars are 
reduced to “islets” sooner than in C. fiver, and the premolars appear to 
have been relatively larger. In these characters this species makes 
some approach towards TYvogontherium+ Jaws of another species, 
C. plicidens, Forsyth Major, first described from the Pliocene of the 
Val d’Arno, have been found in the Norfolk Forest Bed. This species 
is characterised by its broader incisors, slightly larger cheek-teeth, and 
especially by “the complex and elegant plication” of the enamel of 
the molars.” 
Description :—The Beaver is a large heavily-built animal (head 
and body, 820; tail, 380; hind foot, 170), with a rounded water-rat-like 
head, short, heavy limbs, and remarkably modified tail. The upper lip 
is not cleft, and the nostrils are separated by a broad, naked pad. The 
eyes and ears are small: the latter are rounded, with little trace of 
tragus or antitragus, densely clad with hair within and without, and 
almost buried in the fur. The hands are relatively short but quite 
broad ; their palms are naked, and for the greater part occupied by a 
pair of large, rounded pads, which fuse centrally and represent the 
posterior carpal pads of other rodents; there is little distinct trace of 
the anterior pads normally present; the digits, of which 3 and 4 
are the longest, are short and armed with long, slightly curved, and 
rather flattened claws. The well-developed thumb bears a claw like 
those of the fingers. The feet are very large, about two and a half times 
as long as the hands, with broad, naked, scaly, and wrinkled soles, 
the pads being practically obsolete; each has five long toes, united 
by a strong web which extends to the bases of the claws; the latter 
are in general like those of the hand, but are especially large on 
digits 3 and 4; the claw of digit 2 is “double,” a peculiar laterally 
compressed supplement springing from the ball of the toe beneath the 
claw proper and rivalling the latter in size; digit 4 is the longest, 
slightly exceeding 3 and 5. The tail is of exceptional strength, and 
highly modified as a swimming and steering organ; it is very broad 
the summer of 1893, and so exposing the entrances to the burrows in the banks, were 
purchased by the Zoological Society of London ; of them six lived for some time in 
the Gardens at Regent’s Park (Proc. Zool. Soc., 1893, 612). Cocks informs us that 
these would not eat the rations usually supplied to the Canadian Beavers. Cocks 
has further kindly called our attention to a paragraph in the 7z»mes (30th December 
1913), stating that a local sportsman had killed a Beaver near Dijon, If this 
example does not point to the existence of an inland colony, previously overlooked, 
then it must have followed the Rhone, and its continuation the Saone, for more than 
half the length of France. 
1 Lankester, Aum. Mag. Nat. Hist., 1864, 355 ; Newton, Pliocene Vert., 1891, 50; 
and Hinton, Aun. Mag. Nat. Hist., January 1914, 186. 
2 Forsyth Major, P.Z.S., 1908, 630; Hinton, Amn. Mag. Nat. Hist. January 
1914, 188. 
