ELEPHANT AND MASTODON. 45 



species. In like manner, the existing African Elephant is placed 

 between two extinct species, E. Hgsudricus and E. planifrons. 

 The three plates of sections include only the principal forms 

 requisite to establish the passage. Another extinct Indian species 

 E. Namadicus (to be described in the sequel), which is closely allied 

 to the existing Indian form, comes between it and E. Hysu- 

 dricus, together with a European fossil species, which we believe 

 to be distinct from the Mammoth ; and the gap between the 

 existing African Elephant and E. planifrons is filled up by 

 another well-marked European fossil species, E. priscus (?), pi. 

 13, fig. 7, which is closely allied to the former. This species will 

 also be noticed in a subsequent page. 



We shall now revert to E. insignis, and endeavour to trace the 

 forms which diverge from it in an opposite direction through the 

 Mastodons, the tendency in this series being towards a greater 

 simplicity in the construction of the grinders, and a reduction in the 

 number of coronal segments. 



Fig. 7 «) pi. 3., represents a section of the last upper molar of 

 an undescribed Indian fossil species, named E. Ganesa, in this 

 work. The crown consists of ten principal ridges, with a subor- 

 dinate * talon ' ridge in front and behind. The anterior seven 

 ridges have their summits worn, the two in front being ground 

 down to the common base of ivory, the tooth having been a con- 

 siderable time in use. A small portion is broken off at the 

 anterior end. The disposition and relative proportions of the 

 ivory, enamel, and cement, bear the closest resemblance to those 

 of the corresponding tooth of E. insignis (pi. 2, fig. 6 a), 

 and the number of ridges agrees. The section presents the 

 same chevron-formed character in the ridges, but the interspaces 

 are narrower, the cement is in less quantity, and the layer of 

 enamel is thicker. The common grinding surface of the crown is 

 also less convex. But these differences are so inconsiderable, when 

 taken into account with the range of variation through which the 

 molars run, that «they are practically insufficient for the discrimina- 

 tion of the two species. To guard against error, the sections have 

 been taken in both instances from specimens consisting of the palate 



