92 



FAUNA ANTIQUA SI7ALENS1S. 



successive molars in the upper and lower jaws may be 

 expressed thus : „ , q , ^ in the deciduous molars, and 



4 + 4 + 6 



2 + 3 + 4 



^ ^ _ in the true molars.' This formula, with the excep- 

 tion of the number attributed to the last milk molar of the 

 lower jaw, is precisely the same as that assigned by Dr. Kaup 

 to his M. longirostris, Professor Owen having referred, in 

 almost every instance on this occasion, to Kaup's figures, 

 which he quotes as the types of his descriptions. But he 

 still alludes to Cuvier's Dax specimen of M. angustidens as 

 identical with Kaup's species, although it is represented in 

 the original figure, and described by Cuvier, as three-ridged ; 

 and he states, in the ' British Fossil Mammalia,' that the 

 rich series of analogical facts in the dentition of M. giganteus 

 {M. Ohioticus), would 'now appear to complete the demon- 

 stration of the specific identity of the Mastodon longirostris, 

 and Mastodon angustidens.' ^ 



From these details it will be seen how various and opposed 

 the opinions of the best authorities are, up to the present 

 time, regarding Mastodon angustidens. In eonsequence of its 

 rarer occurrence in the fossil state, the available materials 

 for tracing the dentition of this species are less numerous 

 and complete than in the case of M. Ohioticus. The following 

 descriptions are chiefly derived from specimens in the Paris 

 Museum, the most of which have been figured by M. de 

 Blainville.^ Of the milk or deciduous molars in the upper 

 jaw, the thu'd only has yet been met with in situ in the 

 j)alate. It is well shown, on the right side, in the posterior 

 tooth of the Dax specimen figured by Cuvier^ and referred to 

 above, the crown consisting of three transverse ridges, and 

 an accessory talon of two tubercles, each of the ridges being 

 composed of two pairs of confluent mammillae. A single 

 tubercle juts out into each of the hollows between the ridges 

 alternately with the principal points, causing the trefoil- 

 shaped discs, which the worn teeth present in this species, so 

 difi^erent from the lozenge-shaped discs of M. Ohioticus. The 

 dimensions of this tooth are not mentioned by Cuvier, but it 

 may be gathered from the context of his description that it 

 measured a little above three inches long by about two in 

 width. The same tooth, of the left side of the upper jaw, is 

 seen in a most instructive specimen found by M. Lartet, near 

 Sansans, in the department of Gers, containmg two molars in 

 situ, both of which are three-ridged. Of these the anterior. 



' Odontography, pp. 619-23. 

 2 British Fos. Mam. p. 290. 

 ^ During a visit to Paris, I had tlie 

 freest access to these specimens, by the 



liberal permission of MM. de Blainyille 

 and Laiirillard.— [H. F.] 

 * Oss. Foss. pi. iii. fig. 2. 



