Dr. C. I. Forsijth 3Iajor — Some Rodenisfrom Oeningen. 369 



with the fifth simple molar.^ I have myself collected at La Grive 

 about half a dozen mandibular rami of the same Eodeut, in all of 

 which either this fifth tooth itself or its very distinct alveolus is 

 present. 



The foregoing observations mark another step in advance, for 

 they show conclusively that the fifth lower molar of Lagopsis vern» 

 does not occur ' abnormally,' but that it is a characteristic feature 

 of the species, as it is also in the recent Lagomys. 



The upper cheek-teeth of Lagopsis verus are unknown up to- 

 the present. Deperet has published from La Grive a left palate 

 devoid of teeth, but exhibiting very distinctly the alveoli of the 

 five cheek-teeth ; he assigns this fossil, quite rightly in my opinion, 

 to Lagopsis verusr At the same time he figures and describes 

 the left palate of 'Zogodus Fontamiesi,' ^ in which two cheek-teeth 

 are preserved ; in the memoir alluded to above, I have arranged 

 the latter under the genus Titanomys — T. Fontannesi (Dep.). No 

 mandibles of this 'Lagodus Fontannesi ' are mentioned in Deperet'a 

 first memoir quoted, nor in the later one.^ This circumstance 

 seems to be the reason which has induced Schlosser to suggest that 

 Lagopsis verus and 'Lagodus Fontannesi ' are the same species ; ^ and, 

 unfortunately, Deperet, in his second memoir," inclines towards the 

 same opinion, and has consequently omitted Lagodus Fontannesi 

 from his latest list of the Vertebrates of La Grive,'' Lagomys verus alone 

 being mentioned. It may be asked, what then becomes of the left 

 palate represented in the above-mentioned fig. 17 of Deperet's first 

 memoir, which both writers overlook entirely when they unite 

 together the two so widely different forms of Lagopsis verus and 

 Titanomys Fontannesi. It is somewhat surprising that, according to 

 Deperet,^ more than fifty mandibular rami of Lag. verus have been 

 found at La Grive, whilst not a single one of Tit. Fontannesi is 

 mentioned; and I therefore venture to suggest that the mandibles of 

 Titanomys Fontannesi, which are approximately of the same size as 

 those of the other form, have not been recognized amongst the 

 numerous rami collected. I have myself collected at La Grive over 

 twenty mandibular rami, half-a-dozen of which belong to Lagopsis 

 verus and seventeen to Tit. Fontannesi. Both are figured and 

 described elsewhere, and I will therefore only briefly mention here 

 that, apart from the difference in the cheek-teeth, the anterior pre- 

 molar being the most important in this respect, the two genera 

 present some difference in the shape of the bone as well. The 

 horizontal ramus of Tit. Fontannesi is lower and more elongate; 



1 Arch. Mus. Lyon, iv, p. 164, pi. xiii, figs. 16, l&a (1887). 



^ Loc. cit., p. 164, pi. xiii, fig. 17. 



3 Loc. cit., p. 171, pi. xiii, fig. 19. 



* "La Faime des Mammif. mioc. de La-Grive-Saint-Alban" : Arcli. du Mus.. 

 d'Hist. Nat. de Lyon, v (1892). 



5 Beitr. Pal. Ostr.-Ung., viii, pp. 86, 87 (1891). 



^ Loc. cit., p. 58. 



■' Deperet, " Sur la Classification et le Parallelisme du Systlme Miocene " : BulL 

 Soc. Geol. France, xxi, p. 206 (1893). 



8 Arch. Mus. Lyon, iv, p. 164 (1887). 



DECADE IV. VOL. VI. — NO. Till. 24 



