230 
PROFESSOR OWEN ON THE FOSSIL MAMMALS OF AUSTRALIA. 
Front view of laniary 
incisors, magn., Urotri- 
chus talpoides, Temminck. 
the homologue of the laniariform i 2 in Potamogale ; but the pair of developed inci- 
sors in TJrotricTius are what Dr. Falconer would have described 
as “ approximated and placed collaterally, as in the placental 
Rodents”*; i. e. they are in contact, side by side (Cut, fig. 2). 
In the large African Ferine (Carnassier, Cuv.), with the habits 
and food of the Otter, discovered and called Potamogale by Du 
Chaillu, the first incisor of the upper jaw (fig. 3, i 1) “closely 
resembles a large projecting canine” f. In the lower jaw “the 
first is very small. The second incisor is high, conical, curved ; 
it is sharp-pointed, and resembles a canine “The condyle 
is borne on a distinct neck”§. The low position of the condyle 
(Z»), associated with these laniariform incisors in Potamogale 
(fig. 3), is not alluded to either by Allman (Z. c. p. 11) or by Mivart (Z. c. p. 127). 
It is important in association with the position and jux- Fig. 3 . 
taposition of the laniaries in this large fish-hunting 
Ferine, with regard to the moot question of the car- 
nivority of Thylacoleo and Plagiaulax. 
In Myogale, as in Solenodon, the first upper incisor 
“ is much larger and more vertically extended than in 
any other tooth in the skull. Its crown is triangular, 
it is in contact with its fellow of the opposite side, and predominates more than does 
any other form yet reviewed, except, perhaps, that of Sorex. It is opposed mainly to 
the second incisor of the lower jaw, the first being much smaller This second 
incisor is exceedingly large, pointed and conical” ||. “The canine is a small obtusely 
pointed tooth ^f,” as in Thylacoleo. In Solenodon , Potamogale , and Myogale the laniari- 
form incisors of the lower jaw, to which those in TJrotriclms and Sorex may be homo- 
logous, are divided from each other, at their base, by a very small pair of anterior inci- 
sors ; but the extent of separation is slight, and cannot affect in any appreciable degree 
their piercing power. 
Indeed, to concentrate is to give force, to divide is to weaken. If it be not carried too 
far, divarication may aid in the secondary work of holding the pierced prey : but for 
the primary lethal operation, the base for the grasp of the biting muscles is as broad in 
Thylacoleo as in Fells. An estimate of the concentrated force of these enormous muscles 
Side view of upper laniary and 
mandibular dentition, Potamogale 
velox, nat. size (ex Allman, loc. cit.). 
* X. p. 352 ; XI. p. 435. 
t Allman, “ On the Characters and Affinities of Potamogale ,” Trans. Zool. Soc. vol. vi. (1866) p. 6. I am 
indebted to the accomplished author of the above-cited interesting Monograph for the drawing which is the 
subject of the Cut, figure 1. 
+ lb. p. 7. 
§ lb. p. 11. (Compare this “pedunculate” character with that in Plagiaulax, figure 10.) 
[| Mlvaet, op. cit. Journal of Anatomy and Physiology, vol. ii. p. 124. 
Id. ib. p. 125. “ Scalops. The first incisor is very large, and is opposed to one nearly as long in the 
lower jaw, where the canine is wanting, or represented by a most minute and rudimentary tooth.” — Ib. 
