54 FAUNA ANTIQUA SIVALENSIS. 
British Museum. It is of an age intermediate between the specimens 
ficured in Plate XXXV. 3, and Plate XL. 13. It is very valuable, 
and is believed to be at present unique in Europe. 
Length of fragment of jaw, 15°in. Breadth, 4:3in. Height, 4:1in. Length of 
first molar, 4:in. Breadth, 2°6in. Length of second molar, 5°din. Breadth, 
PEL ( thas 
Fig. 16.—Mastodon Ohioticus. Fragment of upper jaw, with three 
ridges and fangs of last upper molar, also empty cavity in jaw for fang 
of fourth ridge.—B.M. 
Length, 5'lin. Width, 4*in. Height of crown and fang, 7: in. 
Fig. 16 a.—M. Ohioticus. Last true molar, upper jaw, with four 
main ridges and a heel; the first ridge only very slightly touched by 
wear. In Mastodon Ohioticus the upper teeth are distinctly cleft 
lengthwise into two divisions, each division being indistinctly composed 
of a pair of confluent points. The plane of the tooth is oblique, sloping 
from the outside, which is higher, to the inside, which is lower, and 
this relation continues during the wear, the inside being the most worn. 
The inner division, both anteriorly and posteriorly, throws off the 
decurrent talon crests, but in the first two milk teeth the inner division 
is smaller than the outer. Precisely the reverse is seen in lower jaw, 
the inner ridge being the highest and remaining so during detrition, 
while the outer is the lowest but least complex.—B.M. 
Length, 7°3in. Width, 4:in. 
Prats XI. 
Tusks of Proboscidea.! Fragments and sections. 
Figs. 1 and 1 a.— Twisted fragment.— B.M. 
Length measured along great curvature, 40°in. Direct length or chord of cur- 
vature, 28°in. Circumference at proximal end, 12°7in. Circumference at distal 
end, 13:2 in. 
Fig. 2.—B.M. 
Length, 56°in. Circumference at proximal end, 13°65 in. 
Figs. 3 and 3 a.—B.M. 
Length of fragment, 12°2in. Circumference, 12°2in. Greatest diameter, 3°7 in. 
Figs. 4, 4 a, and 4 b.—B.M. 
Length of fragment, 12°7in. Greatest diameter, 7'7in. Smallest diameter, 
5° in. 
Fig. 5.—B.M. 
Greatest diameter, 9°8in. Smallest diameter, 7:2 in. 
Figs. 6 and 6 a.—Fragment of tusk in socket. 
Length of socket, 13°5in. Circumference of tusk, 6°2in. Breadth of incisive 
alveolar margin, 6-2 in. 
Figs. 7 and 7 a.—B.M. 
Length, 68°in. Circumference at proximal end, 11:in. 
Figs. 8 and 8 a.—B.M. 
Length of fragment, 33°in. Circumference at smaller end, 16°5 in, 
1 There is no evidence of any attempt | the plate (with the exception of figs. 6 
made by Dr. Falconer to determine the | and 25) are collected in one place in the 
species to which any of these specimens | British Museum. 
belonged. All the specimens figured in | 
