ELEPHAS PRIMIGENIUS.—TRUE MOLARS. 
101 
lhe plates are rather thick, but mostly with reference to the cement and dentine; 
indeed, all Lexden specimens I have seen vary considerably in the thickness of then- 
plates. 1 
Foreign specimens .—The Museum of the Royal College of Surgeons of England con¬ 
tains several admirable illustrations of lower as well as upper-first true molars, said to 
have been obtained from Ohio, N. America. They are described with Dr. Ealconer’s 
usual fidelity, and need no further reference here, excepting as regards their ridge 
formulae, which do not exceed a? 12 x, and the very attenuated enamel pointed out by Owen 
and Falconer." I have already referred to these teeth in connection with the American 
distribution of the species. 
An upper molar, No. 37,293, B. M., from “ gravel pits ” near Moscow, holds xl2 x in 
5f X2'7 inches with 8 ridges in a space of 3^ inches. The enamel is crimped somewhat 
near the middle of the disk and is thick. 
Several suggestive specimens of this tooth are contained in mandibles. 
A lower jaw figured and described by Falconer 3 displays the first true molar fullv 
worn, and the empty socket of a fragment of the last milk in front with the tips of the 
collines of the penultimate true molar just appearing. 
In the Brady Collection a further stage in the detrition of the molar in question is well 
represented in the mandibles. Nos. 43 c and 44 c. The former is shown (Plate VIII, 
fig. 2). A crown very slightly more worn, with the second true molar just above the gum 
and one of its ridges attrited, is represented by No. 47 and No. 45 of the same collection, 
where several of the anterior plates of the first molar are worn away and two of the 
anterior of the second in use, whilst No. 46 shows only half of the ante-penultimate 
remaining and five plates of the penultimate invaded. 
All these mandibles present considerable discrepancies in size, irrespective of the 
state of wear of the first true molar and its predecessor and successor as they happen to 
be in use or not, and no doubt refer to sexual and perhaps also individual peculiarities; 
thus the maximum length, thickness, and divergence of the rami, in the order of advance¬ 
ment of detrition of the crown just given, are as follows : 
Length of mandible. 
Thickness of 
ramus. 
Maximum diverg¬ 
ence of ramus. 
F. A. S., pi. xiii, fig. 2.—B.M. IC'S inches 
No. 43, Brady Collection. 1 9 
No, 44 ditto ... I 91 
No. 45 ditto . 'oa 
No. 4(1 ■ ditto I 99. 
No. 47 ditto 90 
. JJ 
4 "8 inches 
4- 3 „ 
5 
5- 5 „ 
5 „ 
48 „ 
16 inches. 
16-5 „ 
20- 5 „ 
22 „ 
19 „ 
21- 5 „ 
1 Refer to pp. 80 and 110. 
2 ‘Brit. Foss. Mammals,’ p. 238 ; ‘Pal. Mem.,’ ii, 237, and pp. 1G4 and 171. 
Fauna Antiqua Sival.,’ pi. 13 a and B, and figs. 2 and 2 a, ‘Pal. Mem.,’ vol. i, p. 439, This 
specimen from Germany is preserved in the British Museum. 
14 
