ELEPHAS PRIMIGENIUS.— TRUE MOLARS. 99 



of the detrition of the penultimate true molar/ and, judging from the sizes of jaws, 

 molars, and tusks, and as far as is known of the long bones, the same obtained in the 

 Mammoth. The first true molar ushers in the adolescent stage, when the animal is said 

 to attain sexual maturity. 



TJj^per Molars. — The molar. No. 46,211, B. M., from the Dogger Bank, shown PI. XI, 

 fig. 2, presents the very unusual anomaly of containing only nine plates and two talons, 

 and comparable in that respect with the penultimate and ultimate milk-molars referred 

 to at pp. 90 and 95. The double falcated anterior fang supports the first two ridges, and the 

 posterior talon is intact, so that there can be no question whatever of the ridge formula. 

 The crown is 6 X 2f inches, and contains the very unusual proportion of not less than 

 eight ridges in a space of ^\ inches, there being nearly 0*8 inch to each plate. This 

 arises entirely from an excessive quantity of cement, which appears to take up the space 

 occupied in other teeth by plates. 



A comparison between this anomalous crown and that of a first true molar of 

 JE. antiquus (Monograph, PI. Ill, fig. 2) shows striking likenesses, only that the latter 

 holds cT 10 a? in 7 inches, and its crown is not nearly so broad. 



Upper-jaw teeth, in sitil, are not nearly so plentiful as lower. The Brady Collection 

 from Ilfoed, No. c 1, contains a mutilated palate holding two well-worn crowns, but the 

 right is imperfect, and therefore affords little information of the relative dimensions of the 

 palate region. The remains of large incisive sheaths show that the tusk was fully 

 developed. The left molar appears to me to furnish evidence of a ridge formula of a? 12 a? 

 in 5*5 X 3 inches, and to contain eight ridges in 3^ inches. 



The Woodwardian Museum possesses a molar from Gristhorpe Bay, Yorkshire. It 

 contains x \2 x in 5 X 2^, and holds eight ridges in 2*7 inches, and might be fairly placed 

 with the //«"i^-plated teeth. 



There are two detached upper molars, Nos. 15 and 23, in the same collection from 

 the Cambridge gravels, presenting a ridge formula oi x 12 x; the former is 5"5X2'8 

 inches, the latter is 55 X 2*5 inches, but whilst the former holds eight ridges in 3 inches, 

 the latter shows the same number in a length of 3| inches. A molar from a cave in 

 the north of Spain, holding x \'2, x in 5x2-3 inches, is recorded by me elsewhere.^ 

 The enamel is thick^ like that of Ilford molars, and there is faint crimping of the borders 

 of the ridges. 



Another upper tooth from Cambridge, No. 14, with x 12 x in 7x3 inches, holds 

 eight ridges in 3j inches. 



Another from Langford, near Rugby, in the Oxford University Museum, with the 

 same ridge formula in 5 X 3 inches, has eight in 3 j inches, and shows unusual tldchiens 

 of the enamel or dentine, in other words " thick plates." 



A tooth found in fluviatile deposits of the Thames Valley at Battersea, London, holds 



1 This is well seen at present in the young Indian Elephants lately presented to the Zoological Society 

 of London by H.R.H. The Prince of Wales. 



2 ' Journ. Geol. Soc. Lond.,' vol. xxxiii, p. 537. 



