290 
Phascolomys. 
Röse has described several additional teeth in the Wombat, in- 
cluding some which are evidently premilk teeth, thus in the upper 
jaw there is 73 with a vestigial successor, while below 71 with no 
successor, 2 2 with a large successor, 7 3 with none. 
Phascolarctos. 
Neither LECHE’s nor my specimens appear to show any premilk 
teeth, but he finds a missing incisor which he regards as 73. 
In my specimen, a small calcified incisor is present in front of 
the functional lower incisor, and another uncalcified behind the latter, 
posteriorly is the enamel and dentine germ of a lower canine and two 
premolars none of which attain functional maturity. Similarly in the 
upper jaw is an additional premolar. 
The ante-molar teeth abla as under. 
4 
1004 
"203% 
4 
ppm 4 above and below develops well in front of dpm 4. 
Conclusions. 
Traces of an earlier set of teeth the premilk dentition, are found 
in large number of Marsupials, they may be developed in connection 
with all the incisor teeth, the canines and first premolars, but these 
last are never calcified. 
In the Placentalia structures described as remnants of the pre- 
milk dentition are found in Man, in the Ox and in the Hedgehog, con- 
nected with the incisors, canines and as far back as the 2nd premolar 
(Ox), but these structures are slight and as the dental lamina is know 
to send out numerous irregular growths especially on its labial side 
we must accept them with some reservation. 
London, July 1896. 
1) Röse, Das Zahnsystem der Wirbeltiere. Anat. Hefte, 2. Abt., Ergebn. 
d. Anat. u. Entwickel., Bd. IV, p. 542—591. 
2) LecHe, Studien über die Entwickelung des Zahnsystems bei den 
Säugetieren. Morph. Jahrb., Bd. XIX, 1892. 
3) —, Nachträge. Ibidem, Bd. XX, 1893. 
4) —, Zur Entwickelungsges. des Zahnsystems der Säugetiere. Bibliot. 
Zool., 1895. 
5) —, Die Entwickelung des Zahnsystems der Säugetiere. CO. R. des 
Congres internat. de Zoologie, Leyden 1895. 
6) Hertz, Untersuchungen über den feineren Bau und die Entwickelung 
der Zähne. VırcHow’s Archiv, Bd. XXXVII, 1866. 
