462 MESSRS. BLACK MORE AND ALSTON [June 16, 



Mountains ; and it is widely but locally distributed throughout 

 Britain. Its fossil remains do not appear to have been recognized, 

 except in France and England. 



The molars of this species are distinguished from those of all the 

 other known Voles (except the nearly allied A. rutilus, Pall.) by the 

 development in the adult animal of distinct roots, whence it has been 

 generically separated under the name Hypudceus, Illig.* The 

 enamel-folds are proportionally thicker than in the other species, the 

 cemental spaces are more rounded, and the anterior ones of the first 

 lower molar are more distinctly separated. The pattern, which is 

 liable to slight individual variation, especially in the third upper 

 molar, is as follows : — 

 Upper I. 5 spaces 6 angles. Lower 



>) "• 4 ,, •* » >> 



„ III. 6 „ 7 or 8 „ „ 



We have examined the specimens in the British, Taunton, and 

 Norwich Museums, and in our own collection. 



2. Arvicola amphibius (Linn.). 



1823. Water-Eat, Buckland, Rel. Diluv. p. 18, plate xi. figs. 1-6, 

 12-18. 



1825. Campagnol des cavernes, Cuvier, Ossem. Fos3. v. pt. i. 

 p. 54. 



1846. Arvicola amphibia, Owen, Br. Foss. Mamm. p. 201, fig. 76. 



1846. (?) Arvicola, sp. ?, Owen, ibid. p. 205. 



1847. "Hypudceus spelceus, Cuv.," Giebel, Fauna der Vorwelt, 

 i. p. 88. 



1852. (?) Arvicola antiquus, sp. n., Pomel, Ann. Sc. de l'Auvergne, 

 xxv. p. 361. 



1852. (?) Arvicola robustus, sp. n., Pomel, ibid. p. 362. 



1855. (?) Arvicola, sp.?, Lvell, Man. Elem. Geol. (5th ed.), pp. 156, 

 168, fig. 146. 



1866. Arvicola amphibia, Boyd Dawkins & Sanford, Pleist. 

 Mamm. (Introd.) p. xxxvi. 



1869. Arvicola amphibius, Boyd Dawkins, Q. J. Geol. Soc. xxv. 

 p. 194. 



1870. Arvicola amphibius, Sanford, ibid. xxvi. p. 124. 



Dr. Buckland found the remains of the " Water- Rat " so abun- 

 dant in the Kirkdale Cave that almost every fragment of the osseous 

 breccia which he examined contained teeth or broken bones, several 

 of which he figured. Cuvier examined specimens from the same 

 locality, and found them to agree well with this species, but re- 

 marked that, although larger than the remains from Sardinia and 

 Corsica (= A. brecciensis, see p. 466), they were smaller than the 

 recent A. amphibius. On this observation Dr. Giebel founded his 

 " Hyp. spelceus, Cuv." Prof. Owen, however, found that speci- 



* Dr. Forsyth Major mentions a large species, resembling A. amphibius but 

 with rooted molars, as found in the lignites of Leffe, in Lombardy, but has not 

 yet named or described it (Atti Soc. Ital. Sc. Nat. xv. p. 584). 



