AND A DENTAL NOTATION. 
491 
socket containing the germ of its successor in a vertical line with it ; this is more 
especially the case with the last or hindmost deciduous tooth, because the hindmost 
premolar, its successor, is late in coming into place, and the contiguous true molar, 
which is always formed much sooner, is characterized by its deeply implanted 
fangs, and by the absence of any formative socket in vertical relation to them. 
Without the dissection of the jaws figured in Plate XXXIII., I could have had no 
true or scientific knowledge of the nature of the teeth there symbolized. As I 
availed myself of symbols to denote the signification or homology of the teeth of the 
Phacochcerus in my ‘Odontography’ (pages 549 to 557 , pk 140, 141), I shall sum up 
or indicate in the same way the results of the additional observations recorded in 
the foregoing pages. 
Phase 
Phases of the molar series of the genus Phacochcerus. 
I. 
Plate XXXIII. 
5—5 . id2,dB,dA,m\,m2. 
4—4 3, d 4, m 1, m 2. 
II. Plate XXXIV. figs. 4 and 5, 
III. Plate XXXIV. figs. 6 and 7 , 
6 — 6 . fp2,p3,p4, ml, m2, m3. 
■Z z VIZ. < 
0 — 0 IP 3, p 4, ml, m2, m3. 
5 — 5 . jp 3, p 4, ml, m2, m3. 
4—4 ’ 1jo 4, m 1, m2, m3. 
IV. Plate XXXIV. fig. 13 {Phac. Pallasii), viz. ^ 4, m 1, m 2, m 3. 
__ ^ 4—4 . r»3 , 0 4, m2, m3 / f 0 3, 0 4, m2, m3.\ 
V. Plate XXXIV. figs. 9 and 10, ^ ; viz. ’ ’ ( or ^ ^ ’ ) 
^ ’3-3 fp4, m2, m3 V [^3,^4, m3. / 
3-3 
VI. Plate XXXIV. fig. 1 1, - — - viz. p 4, m2, m3. 
O *■* O 
2-2 
VII. Plate XXXIV. fig. 12, - — - viz. ^4, m3. 
VIII. 
1-1 
1-1 
viz. m3. 
The above symbols express, with regard to the first phase, I. e. g., that there are 
five grinders on each side of the upper jaw, and four grinders on each side of the 
under jaw ; that those above answer to the second, third, and fourth deciduous molars, 
and to the first and second permanent true molars ; and that those below answer to 
the third and fourth deciduous molars, and to the first and second true molars, — of 
the typical dentition. With regard to the second phase, the symbols express that 
there are six grinders on each side of the upper, and five grinders on each side of the 
under jaw: those above answering to the second, third and fourth premolars, and to 
the first, second and third true molars ; those below answering to the third and fourth 
premolars, and the first, second and third true molars — of the typical dentition. 
As to the fourth phase with four grinders on each side of both jaws, these answer, 
3 R 2 
