458 DE. C. I. FORSYTH MAJOE ON 



of Prolagiis, and I feel sure that a close examination of the fossil, if it still exists in the 

 Museum of Montpellier or elsewhere, will confirm my view. 



It remains to enquire whether there is some reason for identifying it with one of 

 the species of Prolagus found in deposits contemporaneous, or approximately so, with the 

 strata of Montpellier in question. Of these there are two: (1) Prolagus {Myolagus) 

 elsanus, which I have mentioned from the lignites of Casino, in the Val d'Elsa, Tuscany ; 

 and (2) " Lagonnjs [Prolagus) corsicanus" described under this name from E,oussillon by 

 Deperet *. The little I have to say of the former will he stated in a separate paragraph 

 hereafter. 



As to the latter, Deperet declares that it agrees in size as well as in all other characters 

 Avith the Prolagus from Corsica and Sardinia, and he therefore describes it under the 

 above name. This proceeding is as it should be ; so long as no differences are traceable 

 between both there is no reason for two specific names. But, so far as my own 

 (ixperience goes, the circumstance of a mammalian species surviving unaltered from the 

 Lower Pliocene to the present era (I have found calcified remains of Prolagus sardus, 

 var. cors'wamis, in an "abri sous roche" of the Neolithic period in Corsica) would be 

 quite unique, and it is a priori highly improbable, even taking into consideration that 

 insular species may become, up to a certain extent, conservative in their character. I 

 therefore incline towards the belief that hereafter characters distinguishing the Houssillon 

 from the island form will be shown to exist. 



The presence of a third lower molar, supposed by Deperet to appear occasionally 

 in the Roussillon fossil, would be such a distinctive cliaracter, since it has never 

 been observed in the Pleistocene species ; but I give further on (pp. 482, 483) what I 

 hold to be tlie real explanation of the fact noticed by Dcp6ret, viz. that the supposed 

 m.. 3 in certain jaws from Roussillon is simply a portion of m. 2, which has been 

 cicciden tally detached. 



Another cliaracter noticed by Deperet in the Ptoussillon species deserves mention here, 

 [n the specimen from this locality first described f it was stated that the three posterior 

 upper cheek-teeth are similar to each other, being " construites sur le type ordinaire des 

 Leporid6s." In the third volume of the ' Memoires ' a second specimen is described % ; 

 in this the " premiere arriere-molaire " (p. 1) differs from the same tooth of the first 

 specimen by " exhibiting on the surface of its posterior lobe a double chevron-shaped 

 enamel fold, recalling the molars of Titanomys. These folds must disappear rather 

 rapidly by effect of trituration, thus explaining their absence on the specimen previously 

 figured, which apparently was more adult." Dej)eret adds that these chevron-like folds 

 exist equally in the corresponding tooth in the specimens of " Lagomys corsicanus " 

 from Bastia (Corsica), although this character is not represented in the figure of the 

 latter published by Lortet §, and he concludes that the above is a complete confirmation 



* Ch. Deperet, " Animaux plioci'nes du Rous.sillo:i," Jlt'in. !Soc. Gi'ol. France, i. p. 50, pi. iv. figs. 27-^5 (1S90) ; 

 lii. p. 122, pi. xii. figs. 1, 1 (( (1.SU2). 



t Mom. Soo. Gcol. Frauee, i. p. 57 (1890).. 

 X. Op. cii. iii. p. 122, pi. xii. figs. 1, 1 a (lS92j. 

 § Arch Mus. Lyou, i. pi. viii. 



