ELEPHANTIDJ^. 13 



14756. The hinder ridge and talon of the second left lower true 

 (Fig.) molar ; from Perim Island. This specimen is the type of 

 the species, and is described and figured by Falconer in the 

 Quart. Journ. Geol. Soc. vol. i. p. 361, pi. xiv. fig. 1, and 

 is also figured in the ' Fauna Antiqua Sivalensis,' pi. iii. 

 fig. 11, and in ' Falconer's Palasontological Memoirs,' Tol. i- 

 pi. vi. fig. 3. Presented by Miss Pepper. Before 1846. 



1278. Cast of a cervical vertebra. The original was obtained from 

 Perim Island, but it is not known where it is preserved ; 

 it is referred to this species on the authority of Falconer. 



No history. 



40845. A cast, apparently made from a portion of an incisor. This 

 specimen is labelled in Falconer's handwriting " Dino- 

 iherium indicum. Perim. Cast. Duckworth." If rightly 

 determined, it apparently indicates that the anterior border 

 of the tooth was much sharper than in D. yiganteum. 



Presented by 0. Falconer, Esq., 1867. 



Family ELEPHANTID.E. 



The teeth of the milk- and true molar series succeed one another 

 in a horizontal direction, and, at the most, there are never more than 

 portions of three such teeth in use at the same time. Milk-molars 

 are always present, and are usually three in number; but it is 

 probable that a fourth (mm. 1) is occasionally developed. Premolars 

 may be absent or present ; when present there are usually two on 

 either side of each jaw, but in the North- American Mastodon 

 productus 1 there appear to be three such teeth. There are never less 

 than three ridges in mm. 4, m. 1, and m. 2 2 ; and m. 3 always has 

 one or more ridges in excess of m. 2. The cheek-teeth may have but 

 few low transverse ridges with open valleys, or these ridges may be 

 divided into columns having a somewhat alternate arrangement, or 

 they may be very numerous and developed into tall thin plates, with 

 the intervening spaces entirely filled with similar plates of cement 

 A median longitudinal cleft is present in the cheek-teeth of the less 

 specialized forms. The upper cheek-teeth are always convex antero- 



1 See Lydekker, ' Palseontologia Indica ' (Mem. Geol. Surv. Ind.), ser. 10 

 vol. i. p. 200. 



2 These three teeth are frequently termed the " intermediate molars." 



