52 FAUNA: ANTIQUA SIVALENSIS. 
Figs. 3 and 3 a.—WM. latidens. Upper molar (first true ?) with four 
ridges and back and front heel.—B.M. 
Length, 4° in.; width, 2°3 in. 
Figs. 4 and 4 a.—M. Perimensis. Fragment of upper molar showing 
two ridges and part of a third. The valleys are transverse, but are 
interrupted in the middle by an accessory lobule in front of and behind 
each ridge, and the outer termination of each ridge is bounded by a 
large mammilla, exactly as in Mastodon latidens.—B.M. 
Figs. 5 and 5a. MM. Perimensis. Fragment of lower jaw with 
portion of true molar, presenting a similar arrangement of mammille 
to that noted under fig. 4. 
Length of fragment of molar, 5:4 in. ; width, 32 in. 
Figs. 6 and 6 a.—Mastodon longirostris. Fragment of right lower 
jaw of young calf showing the series of three milk molars in situ. The 
third milk molar is nearly intact; the four ridges of which it is com- 
posed are seen to be transverse, compressed, and composed of a number 
of little points; the valleys are open, with the exception of a tubercle 
in the first, and two or three minute tubercles in the last valley, which 
in no way interrupt their transverse continuity. The back talon formsa 
low transverse free ridgelet as in the Mastodon latidens of India. The 
enamel is irregularly wrinkled, but exhibits no vertical fluting, as in 
M. Arvernensis (See Plate XXXVI. fig. 7). The original specimen 
from Eppelsheim was formerly in the Earl of Enniskillen’s collection, 
but is now in B.M. It is also figured by Kaup (‘Oss Foss. de Darm- 
stadt,’ Plate XX. fig. 2.) 
Length of first tooth, 1:°2in. Width, ‘9 in. Length of second tooth, 1:8 in. 
Width, 1°5in. Length of third tooth, 2°6in. Width, 2:1 in. 
Figs. 7 and 7 a.—Mastodon angustidens. Third? milk molar upper 
jaw, the crown consisting of three transverse ridges and an accessory 
talon of two tubercles. A single tubercle juts out into each of the 
hollows between the ridges alternately with the principal points, 
accounting for the trefoil-shaped discs, which the worn teeth pre- 
sent in this species, so different from the lozenge-shaped discs of J/. 
Ohioticus. This specimen is from Mr. Edward Charlesworth’s collec- 
tion, but there is no history as to its origin.—B.M. 
Length of tooth, 2°8in. Width, 1°6in. 
Figs. 8 and 8 a—WM. angustidens. _Antepenultimate or first true 
molar, having the crown divided into three distinct ridges, with a small 
back talon. 
Length, 46in. Width, 2°6in. 
Figs. 9 and 9 a.—WM. angustidens. Penultimate molar of upper 
jaw, consisting of three ridges and a talon appendage of two tubercles 
behind. The two anterior ridges are affected by wear; the last is 
almost intact. The intervals, wide and deep, have only a single 
mammilla connecting the ridges, about the middle. The crown is 
very simple, each ridge consisting of two pairs of points. The tooth 
has a strong impression in front, is narrow in front and widens behind. 
The drawing is taken from a cast in B.M. The original specimen was 
what Cuvier commenced his account of the species, and it is figured by 
f=) 
him in ‘ Divers Mastodontes,’ p. 255, and Plate I. fig. 4. The dimen- 
