58 Dr. Ss Bwindi on Fossil Bones from Memphis, Tenn. 
smaller 1‘8 inch. This, from its greater size, as well as from tin 
existence of a radimentary fourth ridge, was probably the fourth 
tooth in the se ¢ 
: “The sPaeotita sf the fangs, as well as the grinding down: of 
the crown have een carried so far, that it seems quite probable 
that it actually had been, or was just upon the point of being 
shed. 
“No. 3. Tooth of Megalonyr laqueatus Harlan. —This t ott 
which is represented of its natural size in the adjoining figures, 
(figs, 1 and 2,) has the grinding 
surface perfect, but the opposite 
extremity is broken off. ‘The 
form of the grinding portion is 
elongated oval, has an excavation 
in the middle, which is continu- 
1-6 inch, anal its transverse 0-8 
tooth there exists a strongly pro- 
jecting ridge, vee extends from 
the crown tot On the 
ground surface, thee distinct por- 
tions may be discovered, viz., Ist, 
a central one (fig. 2 a), con sisting 
of ossified pulp, osteo-dentine, 2d, 
a middle portion (b) of dentine, 
and 3d, an outer incrustation of 
crusta petrosa, (c). ‘The outer 
edge of the dentinal portion 
formsa sharp and prominent ridge 
around the circumference of the 
At the broken end, the ale cav- 
ity is quite large, having walls of _ Figs.1, 2 Upper Toath of Megalonyx—nat- 
only about (2 inch in thickness, “"Fig 1" inner faee. eb 
i Fig. 2, crown.—a. Osteo-dentine, 5. De 
7 with a compact ,# 3 tows perrose. | 
4 
S| 
* With regard to the succession of the teeth of the lower jaw of the Mastodon, ~ 
the soggeb B rule holds good: the Ist and 2d molars have each two transverse 
; 3 a with an anterior = Bape basal ridge; 4th, has three | 
ble 
ri 
ridges ° wi be , 
larger ; 6th, a ou ri rapier s “Aili ith, five ridges and a talon. 
See Owen's tography, p. 620; a J. B.S. Jackson, M.D., Proceedings of Bost. 
