Teeth in the Centetide. 527 
Microgale Dobsoni. 
Stage I. All molars functional. In the upper jaw the whole 
of the milk-teeth are still present, with the exception of 
I.d.3, which on each side is replaced by its successor. 
The two Z.1 commence to protrude behind the /.d. 1. 
In the lower jaw I.d.1, I.d.3, P.d.3 on each side, and 
P.d.1 on the right are replaced. 
Stage II. Like I.; in addition, however, P.d.1 is also re- 
placed in the upper jaw, and the same tooth on the left 
in the lower. Among the adult specimens, ¢. e., those 
in which the milk-dentition is replaced completely, there 
are several in which the skulls are shorter than that of 
this stage. 
Stage III. Like IJ., with the trifling difference that P.d. 1 
enf. is replaced on each side. 
Stage LV. In the upper jaw P.d.1, P.d.3, and .d. 3 on both 
sides, and J.d.1 on the right are replaced; in the lower 
jaw P.d.1, P.d.3, I.d.3, and I.d.1. Id. 2 is about to 
be shed above and below. 
Microgale Cowani. 
Stage I. All milk-teeth are ¢m s¢éw and functional. J. 2 is 
almost completely through the gum, and 1.3 is com- 
mencing to protrude. 
Stage I]. Milk-teeth as in I. All three molars functional. 
In the upper jaw J. 3 on the left is beginning to protrude 
behind and on the inside of J.d. 3. 
Microgale Thomast. 
Stage I. All milk-teeth functional: no trace of their succes- 
sors yet visible. M.3 not yet completely protruded. 
According to what has been stated above, in Oryzoryctes 
the milk-teeth are replaced in the following order:—Jd. 3, 
Id.1, I.d.2, P.d.3, P.d.1, P.d.2, C.d. In Microgale the 
replacement of I.d. 1 sup. and J.d. 2 takes place later, in conse- 
quence of the powerful development of its root. According to 
what has been stated in the case of Oryzoryctes tetradactylus, 
the milk-teeth appear in the same order as their successors. 
In connexion with the foregoing a few remarks may here 
be introduced on tooth-formule and tooth-change in the 
Solenodontide and Potamogalide, which are closely allied 
to the Centetide. 
