S36 



FAUNA ANTIQUA SIVALENSIS. 



tlie canines had dropped out, and the two alveolar cavities 

 are exposed, showing that the fang was comparatively short, 

 and much dilated, evincing a resemblance in this respect to 

 the canines of the Seals. 



We have nothing to indicate what the lower canines were, 

 but it is legitimate to infer their existence and correspondence 

 with the upper teeth. 



The molars in the upper jaw of Enliydriodon were, as in 

 Enhydra, four — two false molars, a carnassier, and a tuber- 

 cular. This is seen to have been the number in both the 

 fossil species with which we are acquainted. The first, or 

 precanine, was a very small and rudimentary tooth, deci- 

 duous in the advdt animal. The alveolus for it is dis- 

 tinctly shown on both sides of the head, fig. 2, which 

 belonged to rather a young animal, and j)robabl)^ a female,* 

 as the tooth is retained longer by this sex than by the other. 

 The second had two fangs, and instead of having the flattened 

 form which it has in the Otter, terminating in a pointed 

 cusp, it apjDears to have been short, thick, and blunt, as in 

 Efihydra. It was encircled by a rugged basal ridge, or burr. 

 None of the specimens show more than a section of it, the 

 crown being broken off in all of them ; but the form and burr 

 are best seen in the left side of the old head, fig. 5. 



The upper carnassier is singularly remarkable in the form 

 of its coronal lobes generally, and in the extent and com- 

 plicated development of its interior portion. It constitutes 

 the most typical feature of the genus, and has nothing that 

 we know of analogous to it in the family of Carnivora, fossil 

 or recent. It was remarked both of Liitra and Enhydra, that 

 their carnassier was more or less triangular in its outline. 

 In Enliydriodon it is nearly square ; and instead of the cusps 

 and trenchant ridges of Lutra, or the flattened inequalities 

 of Enhydra, the coronal lobes are developed in conical 

 mammillse, somewhat like those of the mastoid-toothed Pachy- 

 dermata. Fig.^ represents a perfect carnassier detached, 

 of the left side of the smaller siDecies. It is divided by a 

 deep lougitudiiial flexuous hollow into two portions ; the 

 outer or typical body of the carnassier is distinctly three- 

 lobed, the middle lobe being the largest and elevated into a 

 conical mammilla, the other two being blunt tubercles. The 

 inner portion, equalling the size of the outer, is composed of 

 two thick conical mammillse, separated by a deep hollow ; the 

 anterior mammilla has its posterior margin notched near the 

 base into two additional denticular lobules. The posterior 



' This conjecture and the grounds ^ This specimen has been unfortu- 

 ■upon which it is founded were suggested nately mislaid, and was never figured, 

 by Prof. Owen. It is not in the British Museum.- — [Ed.] 



