PART 1.] 
Lydekher: Notices of Siwalih Mammals. 
73 
in fig. 5, Plate XXX, of tlie “ Fauna Antiqna Sivalensis; ” tlie latter, however, 
carries eight, in place of seven ridges, the number of ridges frequently varying 
by one or more in this tooth. The last lower molar of S. insignis carries from 
11 to 13 ridges, and that of 8. homhifrons 9 ridges; the latter tooth is further 
distinguished from the last lower molar of 8- eliftii by carrying a large number 
of cusps on the ridges, whereas there are only four or five on the last lower molar 
of 8. eliftii. The iddge formula of the true molars of 8. eliftii will therefore 
now be as follows :— 
_ 
6 + 6 + (7-8) 
Stegodon homhifrons and 8. sinensis. 
A considerable number of molar teeth of other species of 8tegodon have lately 
been collected by Mr. Theobald, among which there are some which call for a 
short notice here ; most of these teeth belong to the “ intermediate molars.” It 
may be well to state here that the whole of the ridge formula of the molars of 
8. insignis has been determined by Dr. Falconer (“ Palaeontological Memoirs,” 
Vol. II, p. 86) and is as follows :— 
Milk-molars. M ol ars, 
2 + (5-6) + 7 7 + 8 + (10-n) 
2 + 5 + 7 ^(8-9) + (ll-13)‘ 
The ridge formula of 8. ganesa is considered by Falconer to be the same: 
the whole ridge-formula of 8. homhifrons is not known, but it will be gathered 
from the figures in the F. A. S. that it is lower than in ; the third 
milk-molar has six ridges. (F. A. S., PI, XXIX A, fig. 1.) Of Stegodon eliftii 
the ridge-formula of the anterior teeth is not known ; the two first true molars, 
however, carry each six ridges, and I have ah’eady given their formula. 
Having premised this much, our comparisons will be the more easily made. 
The first among Mr. Theobald’s specimens to which I wish to call attention is a 
portion of a maxilla, containing the last milk-molar, and the first true molar, 
the latter tooth I shall often refer to as a; the former tooth appears to have carried 
six ridges, but is much worn; the latter carries six ridges, and fore-and-aft talons, 
the former joining the first time ridge in the middle; there is a slight tendency 
to a median division in the ridges, especially the anterior ones ; each ridge carries 
fourteen or fifteen tubercles, and the four last ridges are much curved. The 
dimension of these teeth are as follows:— 
Length of third milk-molar . . . . . 4’1 
Width of „ „ ..... 2’3 
Length of first true molar ..... 5-9 
Width of „ .3 0 
Interval between 3rd and 4th ridges of first true molar . . I'O 
Xow, it is quite clear, from the number of ridges carried by the first true molar, 
that these teeth cannot belong to 8. insignis or 8. ganesa; the first molar agrees 
with the homologous tooth of 8. eliftii in carrying side ridges, but differs in form 
* The ridges of milk-molar 2 are given as 5, in the specimen represented in F. A. S., PI. XIX., 
fig. 1. 
K 
