FOSSIL AJND EECENT LAGOMOKPHA. 457 



of the enamel folds of m. 1. In rare cases, very young m. 2 likewise show at the same 

 place a diminntive circular enamel islet, fig. 16 (m. 2). 



The deciduous teeth (PI. 36. fig. 4) are scarcely different from those of the preceding 

 species ; but in these teeth also the crescentic cusj) " 6 " does not completely divide the 

 two enamel folds. D. 3 is triangular; d. 2 in younger stages somewhat approaches to 

 a triangular contour. 



Pkolagus LOxoDrs (Gerv.). 



Lepus sp., Gervais, Zool. et Pal. Fr. 1' eil. i. p. .'52 (1818). 



Lepus loxodus, Gervais, ib. ii. explic. pi. xxii., pi. xxii. fig. 9 (1848-52). 



Lagomys loxodus, Gervais, Zool. et Pal. Fr. 2' ed. p. 50 (1859) ; id. Zool. ct Pal. geu. p. 148 (1867-69). 



? Lagorivjs {Prolagus) corsicaniix, Deperet, M(>m. Soc. Geol. France, i. p. 56 (1890), iii. p. 122, pi. xii. 



figs. 1, Iff (1892). 

 'iMyolagm elsanus, Forsytli Major, Atti Soc. Tosc. So. Nat. i. p. 229, 238 (1875), &c. {vide infra). 



Gervais' Lagomys loxodus has been a stumbling-block for fifty years, owing, as I 

 think, to the circumstance that the pattern of the four posterior right upper cheek-teeth 

 preserved had not been grasped and was incorrectly represented. An inspection of the 

 original specimen would at once settle the question; but since I am not acquainted with 

 the original, I must deal, as best I can, with the pul)lished figure and Gervais' incom- 

 plete description. 



The figure is four times natural size. Gervais' desci'iption runs as follow^s: — "DifFere 

 des Lagomys actuels et diluviens par la forme ovalaire et sublosangique des doubles lobes 

 de ses seconde a quatrieme molaires superieures ; la molaire anterieure est en meme temps 

 plus forte, et elle a ses replis plus compHques ; — taille sensiblement inferieure a celle du 

 Lapin de Garenne"*. It was found in the town of Montpellier, in the fluviatile 

 Pliocene marls f. At the same locality, under the Palais de Jiistice, was found the 

 Semnoplthecus monsjjessulamis; and this circumstance is of imjiortance, as proviu"- 

 that these fossils belong to the older of the two faunas, mixed together under the 

 designation Montpellier. SemnopithecMs occurs also in the Lower Pliocene of Casino 

 (Tuscany). 



The reason for which Gervais considered the teeth to be the first, second, third, and 

 fourth is obvious ; the last in the series is equal in shape to the penultimate, Avhile in 

 Layomys the last molar has a postero-internal apjjendage. I believe them to be the 

 second, third, foiu'th, and fifth (p. 2, p. 1, m. 1, m. 2) of a species of Prolagus, because the 

 anterior tooth has the characteristic triangular outline of p. 2 of Prolagus, with the apex 

 turned inward [cf. pi. 36. figs. 10, 21, 24, p. 2). In further agreement Avith Prolagus, 

 Gervais' figure of this tooth exhibits on the outer side two enamel loops ; on the inner, 

 one. The more minute features of this tooth, as well as of those following behind, were 

 not recognized, and therefore the latter have been represented in the manner in which 

 lagomorphous upper teeth generally were and still are, founded on the belief that they 

 are composed of two distinct lamellce closely connected. 



In my opinion there is not the slightest doubt left that we have to do with a species 



* Zool. et Pal. Fr. 2" cd. p. 50. t L. c. 



SECOND SERIES. — ZOOLOGY, VOL. VII. 64 



