626 RODENT-REMAINS FROM CLACTON-ON-SEA. [vol. lxxix, 



Appendix IV. — Note on the Rodent -Remains from Clacton- 

 ox-Sea. By Martin Alister Campbell Hixtox. 



For the greater part these remains are fragmentary and indeter- 

 minable ; but some of the teeth, including a right m.T, and a 

 fragment of a left m. T and a left m.¥ from Bed q, together with 

 portions of two lower incisors from Bed z, belong to a small 

 vole. Of these specimens the right m.T is the most important. 

 Possessing, as it does, five closed triangles in addition to the 

 posterior and anterior loops, it is clearly referable to the genus 

 Microtus ; and in its small size, enamel structure, and form of 

 the anterior loop, it agrees exactly with many of the teeth ob- 

 tained by Mr. A. S. Kennard and myself long ago, from the brick- 

 earth of Grays Thurrock. The species from Grays is clearly a 

 member of the M. agrestis group, to which I have applied the 

 name M. agrestoides ; and I have little doubt that the Clacton 

 vole is either identical with, or else very closely allied to, the Grays 

 species. 



Mr. Warren has called my attention to the fact that Arvicola 

 amphibius has been recorded from Clacton. This apparently rests 

 upon the authority of John Brown, of Stan way, who, in describing 

 his figure ] of a ' Section of a Freshwater Formation near Walton. 

 on the Essex Coast,' says of Bed 5 : — 



' Peat with subordinate and interrupted beds of marine and freshwater 

 shells. Incisive tooth of water rat, figured in pi. xi, 2, Ueliqu. Diluv.'; 



and on the following page he says, rather more explicitly, 



' Incisor tooth of water-rat, figured in Beliquiie Diluvianse pi. xi, fig'. 2.' 



Buckland, however, states in the explanation of his pi. xi that ' the 

 specimens from 1 to 29, inclusive, are all from Kirkdale ' ; and 

 I think that John Brown meant only to indicate that he had 

 identified the tooth found in his Bed o, with the aid of Buckland's 

 figure of a Kirkdale specimen. The present location of John 

 Brown's specimen is unknown, and nothing can, of course, be 

 based upon such a record. But remains of a water-vole, that is, 

 a species of Arvicola, occur abundantly in the brick-earth at Grays ; 

 and consequently there is no inherent improbability in this early 

 record. 



Part of a right mandibular ramus of a young adult beaver has 

 also been found by Mr. Warren. This has part of the incisor and 

 the four cheek-teeth in place ; and it is not apparently distin- 

 guishable from jaws of beaver (Castor fiber) from the Fens. 



1 Magazine of Natural History, n.s. vol. iv (1840) p. 199. 



