540 Dr. C. I. Forsyth Major on the 
of M. pusilla, which in other respects has undergone less 
compression, this has disappeared. 
In the case of Oryzoryctes tetradactylus and O. niger the 
compression of P.1 has proceeded still further, as is shown 
inter alia by the considerable reduction of the median ex- 
ternal cusps; asin Microgale, three of these cusps are present 
on P.1 of Oryzoryctes, but the middle one is not so pre- 
dominantly developed as in the case of the former genus ; 
the first is somewhat larger, the second smaller than in 
Microgale. The “ protocone”’ still has the same extent as 
on M.1 and is bicuspid. Owing to its more compressed 
form P.1 agrees much more closely with P.2 of Microgale 
than with P.1 in the latter genus. P.2 has undergone even 
more compression: the median external cusps are distin- 
guishable merely as vestiges on teeth which are intact; 
the “ protocone”’ is reduced toa minimum. The perfectly 
secodont P.3 is of considerable height; it projects above 
P.2. Both P.2 and P.3, as well as their precursors, show 
on the blade, behind the main cusp and halfway up between 
this and the alveolar margin, an accessory cusp, the inter- 
pretation of which as the homologue of the metacone of the 
molars has already been discussed.—In Oryzoryctes hova 
even M.1 already exhibits the general outlines of a carnassial 
tooth. In P.1 the compression in the longitudinal direction 
has made to a certain extent still further progress than in 
the case of the other species; the “ protocone”’ is likewise 
bicuspid. £.2 is altogether secodont, without a trace of 
median external cusps or “ protocone.” 
2. Lower Jaw.—In Echinops and Ericulus P.1 and P. 2, 
as well as their precursors in the milk-dentition, resemble 
molars; accordingly even P.2 is provided with a stout in- 
ternal cusp, Osborn’s metaconid, of which a trace is still 
present even on P.3 of Echinops. In the case of Hriculus 
P.d.3, P.3, C.d., and C. have an internal basal margin, 
which is still present on the incisors also; it is much less 
pronounced in Lechinops. P.3 of Echinops has sometimes 
only one root. The canine, which is always single-rooted, 
exhibits now and then a slight median groove down the 
root. 
Centetes—Both P. 1 and P.d. 1 are molariform, but P. 1 is 
larger than the molars. P.2 is a powerful tooth, almost 
resembling a canine; like the corresponding tooth in the 
upper jaw, it is higher than the posterior molars. An indica- 
tion of an anterior basal cusp is found only in certain cases ; 
a posterior basal cusp is present in the form of a talon, which 
