201—20 
SIWALIK AND NARBADA PROBOSCIDIA. 
above specimen, is quite like von Meyer’s specimen, but rather smaller. If von 
Meyer’s determination be not erroneous, Dalconer’s ridge-formula for this Trilopho- 
tlon will not hold. 
It thus appears that among the Mastodons, all together nine molar teeth may 
be developed, which may be tabulated as follows : — 
Horizontal series 
Vertical series . 
. 1 
Intermediate molars. 
2 3 4 5 6 
Milk-molars. True molars. 
(2 3 4) {12 3) 
(of type series.) (of type series. 1 
. 1 2 3 
Premolars. 
(2 3 4 of 
type series.) 
Or 
Milk-molars |5| Premolars True molars 
In all species the whole of the horizontal series is always developed ; of the 
preniolar series in one species, the two first (and probably also the last) are developed 
{M. productus) ; in others only the two last (Jf. angustidens, according toPalconer’s 
and my own view, and Jf. latidens), and in others none {M. giganteus, M. sivalensis). 
In the elephants, premolars are only known to be developed in one species 
[E. planifrons): all the horizontal series are developed, but the isomerous ridge- 
formula of the intermediate molars is not preserved in tlie more specialized forms. 
We now come to the consideration of the rest of the dentition of the Elephantidce, 
which need not detain us long. In the upper jaws of all species there are 
normally developed a single pair of tusk-like incisors, wdiich apparently correspond 
to the outer pair of the three typical mammalian incisors. In the females these 
tusks are usually smaller than the male ; in some species, however, {E. africanus), 
the tusks are frequently large in both sexes. In one variety of the Indian elephant 
the Miikna (Mooknah), the tusks of the male are small, like those of the female. 
In the living species, and certainly in some fossil species, of ElepliantidcB, the per- 
manent tusks were preceded by deciduous tusks : it is probable that this replace- 
ment occurred in all members of the family. 
In many Mastodons {M. longirostris,M. angustidens) a pair of tusk-like incisors 
were also developed in the lower jaw, but it is not known whether these were pre- 
ceded by deciduous incisors. In, at aU events, one species [M. angustidens) inferior 
tusks were developed in both sexes in others {M. longirostris, M. perimensis) 
in only one sex, which was doubtless the male : in other species again ( Jf. sivalensis 
M. latidens, M. falconeri), there appear to be no lower incisors ever developed. In 
no elephant is there ever any trace of lower incisors. 
It will be apparent from the above summary that no generic determinations 
of the Elephantidce can be made from the presence or absence of certain teeth. 
* Prof. Owen, “ Odontography ” p. 615, gives no lower tusks to the females of all species, hut to all males of 
the genus. 
