CANIDAL 555 
of the four molar teeth as a survival of a condition of the dentition 
exhibited by the common ancestors of the existing Canide and the 
existing carnivorous Marsupials. There is, however, at present no 
paleontological proof of this, as none of the numerous fossil forms 
of Canide yet discovered have more than the normal number of molars. 
Extinct Genera.—A large number of fossil Carnivora have been 
described from various Tertiary deposits which are more or less 
closely allied to the existing Canide, although, as already men- 
tioned, connecting the latter so closely on the one hand with the 
Vwerride and on the other hand with the Urside, that it is almost, 
if not quite impossible to say where one family begins and the other 
ends. A few only of the more important of these annectant types 
will be mentioned here. Temnocyon, of the Miocene of the United 
States, is a true Dog, which agrees with Icticyon in having a secant 
hind talon to the lower carnassial, but preserves a generalised char- 
acter in having an entepicondylar foramen to the humerus. An 
extremely interesting form is Cynodictis, of the Middle Tertiaries 
of Europe and the United States, which (as now restricted by 
. Dr. Schlosser) includes a number of species mostly not larger than 
Foxes. The dental formula is generally the same as in Canis, but 
(as in that genus) the last lower molar may be absent. The teeth 
are very like those of the V’iwerride, the lower carnassial never being 
greatly elongated antero-posteriorly, and its inner cusp being situ- 
ated immediately on the inner side of the hinder lobe of the blade, 
instead of somewhat behind it, as is the case in most Dogs. In 
the skull the auditory bulla is inflated, but is said to have no 
distinct septum; while the humerus invariably has an entepicondylar 
foramen. It is suggested that Cynodictis is not far removed from 
the ancestral type of many of the Viverroids and Canoids, and may 
itself have been derived from the undermentioned genus Amphicyon. 
M. Boule considers, indeed, that from the resemblance of the Plio- 
cene Canis megamastoides (p. 553) to Cynodictis we ought to regard 
the Foxes and Jackals as the descendants of Cynodictis, while the 
Wolves have been derived directly from Amphicyon. The last 
named genus, which includes some species as large as a Bear, is 
found in the Upper Eocene and Lower Miocene of Europe, and is 
represented in the Miocene of the United States by the allied 
Daphenus. It is characterised by the presence of three upper 
molars—thus bringing up the dental formula to the full Eutherian 
number ; by the five digits on all the feet, which were plantigrade; 
and by the presence of a third trochanter to the femur and an 
entepicondylar foramen to the humerus. The teeth are essentially 
those of a dog, and the base of the skull is also dog-like, although 
it is highly probable that the auditory bulla had no trace of a 
septum. According, however, to Dr. Filhol! the minute foramina 
1 Arch. Mus. Lyon. vol. iii. art. 1, p. 85 (1881). 
