i60 DE. C, I. FOESYTH MA JOE ON 



narrow enamel fold — more distinct in the left-hand tooth — corresponding to a shallower 

 and wider fold in Tltanomijs, which forms the anterior houndary of a minnte terminal 

 cusp, marked " t" in the figures {Titanomys, PL 37. figs. 2, 3, 7, 2.5). More ahoiit 

 the significance and the homologies of this terminal cusp will he said in the chapter 

 treating of the lower cheek-teeth. I mention it here, since in no other species of 

 Prolagus have I met with it in p. 2, and it may therefore be characteristic of Pmlmjus 

 elsamis. 



The only teeth known from Casino are mandibular ; and as tliose from Montpellier 

 are maxillary, no direct comparison can be made between them. Both deposits are 

 contemporaneous, and bear other species in common; wherefore there are good grounds for 

 assuming the specific identity of the remains of Prokujus from the Italian with those of 

 the Prench deposit. If this can be satisfactorily shown in the sequel, Gervais' specific 

 name will have to replace mine on grounds of iiriority. 



3. Genus Lagopsis, Schloss. 

 Lagopsis verus (Hensel). 



Lagornys wningensis, H. v. Meyer, Neu. Jahrb. 183G, p. 58, p. p. ; id. Foss. Saugethiere &c. vou CEniugeii, 

 p. 6, pi. iii. fig. 1 (1845) ; Biedermann, Pcti-efacten aus d. Umgeg. v.Wintertliur : II. Die Brauiikohleii 

 von Elgg.p. 13, pi iii. figs. 1, 2, 3 (1863) ; Lydekkcr, Cat. Foss. Mamin. Brit. Mus. i. p. 256 (Specim. 

 Br. Mus. nos. 42815, 42816 (?), 42820 (?) (1885). 



Lagmnys verus, Hensel, Zeitschr. deutsch. geol. Ges. viii. ]). 688, pi. xvi. figs. 12, 13 (1856) ; Deperet, Arch. 

 Mus. Lyon, iv. p. 164, pi. xiii. figs. 16, 17 (188/). 



Titanomys mningensis, H. v. Meyer, Palseontogr. xvii. p. 228 (1870), p. p. 



Lagomys {Lagopsis) wningensis, ScMosser, PalaeontogT. xxxi. p. 31 (1884), p.p. 



Lagornys [Lagujtsis) verus, Sclilosscr, op. cit. p. 31, pi. xii. figs. 40, 46, 49 (1884) ; Deperet, ArcL. Mus. 

 Lyon, V. p. 57 (1892), p. p. 



Hensel's type-specimen is a mandibular ramus, and will therefore be more fully 

 discussed in a later chapter. He was impressed by its approaching much nearer the 

 recent Lagomys than the remains of Prolagus [''Myolagus") described in the same paper. 

 ■' Ich nenne die Art Lagomys verus, weil sie sich durch die Zahl ihrer funf Backenzahne, 

 durcli die Stelluug des Eoramen mentale iind durch den ersten unteren Backenzahn, der 

 uui- aus einem Cylinder besteht, als ein achter Lagomys ausweist " *. 



It is perfectly triie that this fossil is closely related to Lagomys. However, Schlosser 

 proposed to raise " Lagomys oeningensis, H. v. Mey.," and " Lagomys verus, Hens.," to the 

 rank of a genus, Lagopsis, a position with which I in general agree, while I disagree in 

 part with the reasons assigned for it. There is no doubt that some of the larger Lagomyidse 

 of QEningen, which were comprised by H. v. Meyer under the above name, are identical 

 with Hensel's Lagomys verus ; but with regard to other specimens this has not yet 

 been demonstrated. We cannot therefore throughout regard " Lagomys aiiiliigeusis, 

 H. V. Mey.," as synonymous with " Lagomys verus, Hens.," as Schlosser has hesitatingly 

 assumed in his ' Nager des europ. Tertiars ' (p. 32) and more positively asserted later f, 

 followed by Lydekker %. 



* Op. cit. pp. 688, 68'J. t Beitr. Pal. Oestr.-Ung. viii. p. 86 (table) (1890). 



t Cat. Foss. Mamm. Brit. ilus. i. p. 256 (1885). 



