Descriptions of East Asiatic Mammals 143 
through gristle and tendons. The lower one of these teeth is the 
first lower molar, a permanent tooth ; its functional upper coun- 
terpart is not the first upper molar as one might expect, but the 
fourth premolar, a tooth that at the end of puppyhood, kitten- 
hood, or cubhood replaces the temporary or "milk" fourth pre- 
molar. These two "sectorial" teeth at their fullest development 
each bear a large, blade-like cusp. The edges of these cusps work 
together like the blades of scissors. 
Among the more highly predaceous members of the order, 
such as the Cats and Dogs, the whiskers on either side of the 
muzzle are strongly developed. Predaciousness manifests itself 
in the Cats by the stealthy approach and the sudden spring, in 
the Dogs by ability to run down the victim. The feet of the Cats 
are soft, cushioned, and armed with sharp retractable claws, 
while those of Dogs are hard and tough, with a tendency toward 
reduction of the outer and inner toes; the first (innermost) toe 
may be absent. In both of these types of carnivores the hind part 
of the foot is furry and kept well above the ground in walking. 
In the slower-moving Bears all five toes are retained and in 
walking the entire foot to the heel is often placed on the ground. 
The Carnivora are divided into two primary divisions, the 
recognition of which, though not at all obvious, is based upon 
fundamental differences of anatomy, particularly the conditions 
of the ethmoturbinal bones of the inside of the nose and the 
structure of the resonating chamber of the ear. The first group, 
the Arctoidea, from the Greek word meaning "bear," contains 
the Dog family, Canidae, the Bear family, Ursidse, the Greater 
and Lesser Pandas, placed in separate families by themselves, 
and the Weasels, Badgers, and Otters, Mustelidae. The Ameri- 
can Raccoons, Procyonidae, belong also in this latter division. 
The second group, the Aeluroidea, from the Greek word 
meaning "cat," includes the Cat family, Felidae, the Hyaenas, 
Hyaenidae, the Civets, Viverridae, and the Mongooses, Herpes- 
tidae. 
