FOSSIL THYLAC1NUS. 
455 
scribed in the Catalogue of the College of Surgeons, under 
the name 
Thylacinus spelceus. Owen. 
The principal known differences between this fossil species 
and the recent one are, that the lower jaw is deeper, being 
nine lines below the first premolar tooth, whilst in Thylacinus 
cynocephalus the depth of the jaw at the same point is but 
seven lines. A penultimate molar tooth of the lower jaw in 
the College of Surgeons' Museum, when compared with the 
corresponding tooth of the recent species, “ differs, moreover, 
in having a small accessary cusp on the inner side of the 
large middle compressed cusp, winch cusp is also less deeply 
and angularly divided from the anterior lobe of the tooth . l ” 
In this last mentioned character the fossil agrees more nearly 
with Dasyurus proper, than with Thylacinus. 
1 Owen, in Catalogue of the Fossil Remains contained in the Museum 
of the College of Surgeons, p. 336. 
J 
