194 Mr. M. A. C. Hinton on 



" Monkey Gravel " * — the uppermost part of tlie Upper 

 Freshwater-Bed at West Ruiiton, Norfolk,— Mr. G. White 

 was fortunate enough to find a minute tooth ; its small size, 

 yellowish colour, and form, resembling as it does a few 

 agglutinated particles of the sand in which it was embedded, 

 says much for the sharp sight of my friend. Mr. White 

 very generously presented the specimen to mc. It turns out 

 to be tlie right ^li of a squirrel. It differs importantly from 

 the Pi-* of <S'. vulgaris, and indicates a species which, when 

 more fully known, will probably not be able to find a place 

 within the genus Sciurus as restricted by modern mammalo- 

 gists. For this Forest-Bed species I have pleasure in pro- 

 posing the name of 8. ivhitei. 



In S. vulgaris (PI. Vlll. fig. 9) the outer border of Pii is 

 formed by the four cusps called by Winge 1, 4, 2, and 5 ; of 

 these 4 and 5 are the largest and most lofty, 1 is nearly as stout 

 though lower than either, vv^hile 2 is minute and on its way 

 to disappear. The inner side of ^li is formed by a single 

 very large and lofty cusp (Winge's 6), which Forsyth jMajorf 

 has shown to be a compound of at least three inner tubercles 

 which have fused together. Between the outer cusps and the 

 inner cone is a series of transverse ridges (formed out of a 

 modified median series of tubercles, and comprising, inter 

 aHa, the " proto-" and '' meta-conules "), viz., a low one 

 forming the anterior border of the tooth from cusp 1, two 

 higher ones from cusp 4, and the anterior edge of cusp 5 

 respectively, and a low one forming the posteiior border from 

 the hinder edge of 5 ; between these ridges are three trans- 

 verse valleys, of which the central one, for the reception of 

 the chief cusp of the opposed tooth, is the widest and deepest. 

 Ill the fossil (Pi. Vll L fig. 10) the same elements are present, 

 but the transverse arrangement is less perfect, (yusp 1 is much 

 smaller, as in some sj)ecies of Tamias ; it is compressed from 

 before backwards, and prolonged inwards as a rounded ridge 

 which dies out with the first transverse valley at a point less 

 than halfway across the crown. The remainder of the front 

 border of the looth isfornnd by the " |)r()to-conule,^' which 

 liere retains more of its tubercular character and indepen- 

 dence, being more forwardly |)laced and separated from 

 cusp 4 by a conspicuous cleft. Ousp 2, though very low, is 

 stouter. The " meia-conule " is stouter and move indepen- 

 dent; externally it is placed further back, the hinder trans- 



* llinlon, G(!ol. Mai,', dec. 5, vol. v. p. 440. 

 t For.s^-Lii Mujor, I'roc. Zool. Soc. 18'jy, p. 182. 



