﻿ELEPHAS ANTIQUUS. — RIDGE FORMULAE. 



47 



It can never in the future be the interest of the philosophical naturalist to create new 

 species from a few minor characters. It seems to me, therefore, in order to realise the 

 varying features in dental elements of Proboscidians, that strict cognizance should be taken 

 of talons and the like in computing the ridge formula, which varies in every member of 

 the series, not only in the recent, but in all known fossil Elephants ; at all events, 

 wherever sufficient materials have been obtained. It need scarcely be observed that the 

 following ridge formulas are provisional and liable to extension in accordance with future 

 discoveries. 



1. From the foregoing details it seems to me that the ridge formula of Eleplias 

 antiquus, as far as British specimens in particular demonstrate, is, talons included, in 

 upper and lower jaws, as follows : 



Milk Molars. True Molars. 



I. II. III. IV. V. VI. 



x2x — x3x x5x — x7 x x9x — x]0x x9x — x\2x x\2x — x 13 x xlnx — x 20 x. 



x'dx — 1 x6x — xSx x9x — xl\x a; 1 1 a; — x 12 x xl2x — xl3x x 16 x — x\9x. 



2. The ridge formulas of the Mammoth and Asiatic Elephant according to Falconer 

 are the same •} if anything, there is also a greater range in the former than m E. antiquus, 

 the ultimate molar varying in number from x 19 x to x 27 x. The lowest number of 

 ridges in the last molar of the Mammoth, according to Falconer, is stated to be x 24 x, 

 but Mr. Davies in the describing and naming of the valuable materials collected by Sir 

 Antonio Brady, F.G.S., in the Ilford deposits, records entire ultimate molars of the 

 Mammoth containing nineteen plates and two talons ; 2 consequently, if the extremes in the 

 Elephas antiquus and E. primigenius meet, with the limitation in the lowest number of 

 ridges of the last true molar as just indicated, the ridge formula of the Mammoth as 

 given by Falconer will stand as follows : 



Milk Molars. True Molars. 



I. II. III. IV. V. VI. 



x ^? x 8x — ? x\2x~ ? x\2x — x\4 x xl6x — x \8x x 19a — x24 x . 



x — ? x8x — ? x\2x — ? x\2x-x\Ax xl6x — x\8x x 19 x — x 28x. 



3. The dental formula in the African Elephant appears to vary much, but it seem- 

 ingly never attains to the number of ridges in true molars that is seen in any of the 

 three preceding species. According to Blainville, Owen, and Falconer, none of whom 

 give exactly the same formula, supposing they have not represented more than the 

 exact number of ridges, including talons, it stands thus : 



1 ' Pal. Mem.,' vol. ii, p. 157, and footnote, p. 236. 



2 ' Catalogue of Vertebrata for Ilford,' p. 3. 



