504 Dr. C. I. Forsyth Major — Rodents of W. Mediterranean. 



(3) From the peculiar thickness of the enamel layer.^ 



(4) From the more vertical position of the molar tubercles, 

 whence the specific name given by Hensel.* 



I am, and have always been, so much impressed with the importance 

 to be attached to these peculiar characters of the fossil species, that 

 I deem it necessary to raise it to generic rank. 



III. The Vole from the Pleistocene of Sardinia, Corsica, and 

 Tavolara. 



Akvicola (Tyrrhenicola) Henseli, Maj. 



" Campagnol de Cette, de Corse et de Sardaigne," p.p. Cuvier, Oss. foss., vol. iv, 



pp. 202, 205, 225, pi. xiv, fig. 7 ; pi. xv, fig. 29 ; vol. v, pt. 1, p. 54 (1823). 

 Hypudmus breccienshs, p.p. Giebel, Fauua der Vorwelt, vol. i, p. 88 (1847). 

 Arvicola amhigims, Hensel, Zeitgchr. deutsch. geol. Ges., vol. vii, p. 469, pi. xxv, 



figs. 3, 8, 9 (1855). 

 Arvicola Henseli, Forsyth Major, Atti Soc. Tosc. Sc. Nat., Proc. Verb., vol. iii, 



pp. 126, 127 (1882) ; id., Kosmos, vol. vii, p. 6 (1883) ; Lvdekker, Cat. 



Foss. Mamm. Brit. Mus., vol. v, p. 322 (1887) ; Forsyth Slajor, in De 



Stefani, " Sul Fosfato di Calce della Sardegna," Atti li. Accad. Georgofili, 



vol. xiv, p. 11 (of author's copy) (1891). 

 ^^ Arvicola groups d'amphibms," Deperet, Anu. Soc. Linn. Lyon, vol. xliv, p. 122 



(1897). 



Cuvier was of opinion that the voles occurring in the breccias of 

 Cette, Corsica, and Sardinia are all of one species ; hence the 

 specific name Arvicola brecciensis given to them by Giebel. Hensel 

 proposed for the vole from Bonaria (Sardinia) the name A. ambiguus, 

 which is preoccupied by Pomel's A. ambiguus (= Dicrosfonyx 

 torquatus). From a comparison of the figure of the Cette vole 

 in the " Ossements fossiles " (pi. xiv, fig. 25) with my specimens 

 from Toga (Corsica) and Sardinian localities, I inferred the dis- 

 tinctness of the continental form from that of the islands. The 

 former being the first described (by Cuvier), the name brecciensis 

 remains for the vole from Cette. Having since had, through 

 Pi'ofessor Boule's courtesy, the opportunity of examining the original 

 of Cuvier's figure of the teeth from Cette, I was able to confirm the 

 distinctness of the continental from the insular species. The former 

 appears to be identical with some jaws which I have worked out of 

 the Gibraltar breccia, and belongs to the subgenus Microtus. 



The lower anterior molar (rr/i) of the insular fossil vole has not 

 more than three closed triangles,^ a character which at once excludes 

 the genus Microtns, in tlie restricted sense in which I have recently 

 used this generic term, and places it within the genus Arvicola. 



The complication of the anterior loop in the my of the fossil, and 

 the confluence of the two anterior triangles of wio, both of which 

 characters are features of the subgenus Pitymys, show that the fossil 

 is more closely allied to Pitymys than to the subgenus Arvicola 



1 Ibid. 

 - Ibid. 



•* I have found it convenient, in describing the molar teeth of voles, to adopt some 

 terms used by American zoologists, for which see Gerrit S. Miller, jun., "Genera 

 and Subgenera of Voles and Lemmings," North American Fauna, No. 12, 

 Washington, 1896. 



