4 MR. R. LYDEKKER ON A NEW FOSSIL OTTKR. [Jan. 14, 



as Dr. Schlosser points out, certainly does not belong to that species. 

 With regard to L. franconica, it may be observed that this species 

 was founded on limb-bones, of which the age is unknown, and which 

 may be referable to one of the earher named species, if indeed it really 

 belongs lo Lutra at all. The species represented by the mandible 

 described as L.valetoiii, if distinct from all the other forms, requires 

 a new name. The Siwahk jaw, upon the evidence of which 1 have 

 founded the species L. batliygnathus^, is at once distinguished by 

 the great relative depth of the mandible; while L. palcBinclica-, of 

 the same deposits, is a smaller form closely aUied to L.sumatrana^. 

 Assuming its distinctness from all recent Otters, there accordingly 

 appears to be good evidence that the Eppelsheim mandible indicates 

 a new species, for which I propose the name of Lutra hessica. 



In attempting to define this species from the characters of the 

 lower jaw only, I am fully aware how extremely difficult it would be 

 to distinguish the existing species of Otters upon such evidence 

 alone ; but since the named fossil forms are very few in number, the 

 objection does not apply so forcibly in this case. If, indeed, we 

 examine the lower jaws of existing Otters, we shall find that it is 

 possible to distinguish a large number of them by the characters of 

 the mandible ; some of the most important features being the 

 relative length of the lower carna-sial to that of the last premolar, 

 and the proportionate size of the imier cusp of the former tooth. 

 Thus in the large L. brasiliensis the carnassial is comparatively 

 small in proportion to pm. 4 ; in i. elHoti* (B of woodcut) it is 

 considerably larger ; while in L. cinerea (U of woodcut) the 

 proportionate size of the carnassial attains its greatest development. 

 Again, while the inner cusp of the carnassial is very large in L. cinerea, 

 L. paranensis, and L. brasiliensis, it becomes somewhat smaller in 

 L. vulgaris, and still more so in L. sumatrana, where the entire crown 

 of this tooth becomes very narrow. The carnassial is also narrow, 

 with a rather smaller inner cusp, in the S. American L. felina. 



Now L. hessica is an Otter of slightly larger size than the 

 Oriental L. ellioti, but with very similar proportions in the length 

 of the carnassial and pm. 4 ; the inner cusp of the blade of the 

 carnassial is, however, decidedly larger than in the existing form, in 

 which respect it agrees better with the larger L. brasiliensis. The 

 cingulum on the inner side of the carnassial is more distinct than in 

 L. ellioti, and the inner wall of the talon somewhat higher. The 

 dimensions of the lower teeth of the two forms are as follows, in 



millimetres : — 



L. hessica. L. ellioti. 



Length of pm. 4 + m. I 26 24 



pm. 4 (?) 10 9-5 



m. I 16 15-5 



^ Pal. Ind. ser. 10, vol. ii. pi. xxvii. fig. 3. 



^ Op. cit. fig. 2. 



3 See Thomas, Proc. Zool. Soc. 1889, p. 193, note 1. 



* I provisioually follow Mr. W. T. Blanford in employing the nameZ. ellioti 

 for the Otter in question, since there seems considerable doubt whether Mr. O. 

 Thomas's proposal to substitute the name L. harang will meet with acceptation. 



