486 PROFESSOR OWEN ON THE DENTITION OF PHACOCHCERUS, 
senes is m - — - ; the teeth in both jaws being p4, m2 and m 3 : here the penulti- 
mate premolar has been shed before the penultimate true molar, the socket of which 
however alone indicates it in the lower jaw. 
In a still older specimen, 3 and m2 have been shed in both jaws, and the dental 
series is reduced to ; the teeth being jo 4, m 3 on each side of both jaws (fig. 12). 
Finally, jo 4 is shed, and only the great posterior molar remains, as in the old Phac. 
figured in tab. xviii. of Home’s memoir. 
It is interesting and suggestive thus to observe that an analogous duration or lon- 
gevity, so to speak, characterizes the last tooth of both premolar and true molar 
series ; an analogy so little to be expected from their different size and widely differ- 
ent original position in the jaws, by which characters. Home, not sufficiently extend- 
ing his observations and trusting to the analogy of the Elephant, was misled. 
With respect to the Phac. Pallasii, my opportunities of tracing the course of 
dentition are not so extensive as with regard to the Phac. JEliani. I have observed 
none younger than the specimen figured by Home (tab. xix.), and am not acquainted, 
therefore, with the characters of its deciduous dentition. 
All the four teeth on each side of the upper jaw of that specimen, and there are the 
same number in the lower jaw, belong to the permanent series ; tracing them from 
before backwards they are p 4, m \ , m2 and wi 3 in both jaws. The homologue of p 3 
in the upper jaw of Phac. jEliani, if it be developed, is sooner shed in the Phac. 
Pallasii than in the Phac. ^Uani. From the defects that have been pointed out in 
FIome’s reduced figures of these teeth, more accurate views of them of the natural 
size may be acceptable, especially as they have not been elsewhere represented. I sub- 
join, therefore (Plate XXXIV. fig. 8), a side view and a view of the grinding surface 
of each. These figures, also, preclude the necessity of verbal description. I will only 
state that p 4, in the upper jaw, is implanted by three fangs, and is relatively smaller 
than its homologue in Phac. JP,liani : p 4 in the lower jaw offers corresponding dif- 
ferences with its homologue in Phac. JPUani ; m 2 has a narrower crown in relation 
to its antero-posterior extent than in Phac. jplliani ; and a similar and more com- 
pressed form distinguishes the third molars in both jaws of the Phac. Pallasii. In 
the skull of a female Phacochoerus, called ‘ Haruja,’ from Caffraria, in the British 
Museum, which differs from the typical Phac.^liani of North Africa in having only 
two incisors in each ramus of the lower jaw, the following is the dental formula: — 
. 1-1 1 — 1 2-2 2-2 
the grinders of the upper jaw are p d, p 4, m2 and m 3 : those of the lower jaw are 
p 4,m2 and m 3. The first true molar has been shed, and its place obliterated in 
both jaws. 
