MACH^RODTJS FROM THE FOREST-SED. 311 



These differences are sufficient to indicate the specific distinction 

 of the fossil from the Pikermi and Eppelsheim Maclicerodus. 



In the absence of pm. 3 the fossil agrees with many examples of 

 the Xorth- American M. neorjcBus *, but is distinguished by the smaller 

 size of pm. 4. 



Having now shown that the specimen under consideration is 

 specifically distinct from the Pikermi Maclicerodus^ it remains to 

 consider whether it should be identified with the Val d'Arno M. 

 cultridens (from which the Pikermi form would then be distinct) 

 or with M. latidens (if this be really distinct). A fragment of the 

 upper canine of a Maclicerodus has been described from the Forest- 

 bed by Prof. Lankester f, which he was disposed to identify with 

 M. cultridens rather than with M. latidens ; and this provisional 

 identification, coupled with the occurrence in the Forest-bed of Yal- 

 d'Arno species like Elephas meridionalis, Rhinoceros etruscus, and 

 Equus Stenonis, is in favour of regarding our specimen as belonging 

 to M. cultridens. On the other hand, since the Forest-bed also 

 contains later mammals, such as Eleplias antiquus and primi(jenius, 

 Hycena crocuta^ and Sus scrofa, there is no reason why the Pleisto- 

 cene M. latidens should not also be found there. 



As it appears to me to be at present impossible to say whether 

 M. latidens should be regarded as a well-marked species or merely 

 as a variety of M. cultridens, we must await the discovery of a jaw 

 of the latter in the Val d'Arno before the specific determination 

 of Mr. Backhouse's specimen can be definitely settled ; but from the 

 evidence of Prof. Lankester's specimen I am rather inclined to think 

 that it may belong to M. cultridens ; and in view of this contingency 

 it will be advisable for the future to separate from the latter 

 species the Pikermi and Eppelsheim form, and to retain for it the 

 name of M. aplianistus %> It is interesting to observe that the 

 present Forest-bed jaw evidently belongs to a more specialized 

 species than the latter, as is indicated by its shorter ramus and 

 numerically reduced cheek-dentition. 



EXPLANATION OF PLATE X. 



Right ramus of the mandible of a very old male individual of a species of 

 MachcBrodus, from the Forest-bed of Kessingland, Suffolk. Fig. 1 

 shows the external surface, and fig. 2, the anterior aspect, on a scale 

 of ^ ; i. 3, outer incisor ; c. canine ; pm. 4, premolar ; m. 1, true molar 

 (camassial or sectorial). 



DiSCIJSSIOlT. 



Prof. Flower said there was no doubt about the generic identi- 

 fication, but it was to be regretted that the upper jaw, with its 

 characteristic huge canine, had not also been found. 



* See Cat. Foss. Mamm. Brit. Mus. pt. i. p. 48. 

 t Geol. Mag. 1869, dec. ii. vol. vi. p. 440, pi. vi. 



\ This name is thirty years earlier than Iconinus, and (assuming the identity 

 of the Pikermi and Eppelsheim forms) should therefore be adopted. 



Q.J.G.S. No. 167. , z 



