THE 
AMERICAN NATURALIST. 
VoL. xvii. — MARCH, 1883. — No. 3. 
a 
pe ewe 
Vo poh haha ta 
ON THE EXTINCT DOGS OF NORTH AMERICA. 
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a 
L BY PROFESSOR E. D. COPE. | 
ope 
i HE family of thé Canidæ occupies in the order of the Car- 
~ 'nivora, a position intermediate between the generalized forms, 
as the raccoons, and the highest or specialized forms, as the cats. 
While its sectorial or flesh teeth are well developed, the primitive 
tuberculars remain in the jaws behind them, frequently to the full 
‘number in the superior jaw, and in rarely less than the full num- 
ber in the lower jaw. The sectorials themselves are of inferior 
type, for the superior generally lacks the anterior lobe, and the 
inferior has a large heel, which is frequently tubercular. The 
: number of the toes, generally 5-4, is smaller than in the lower 
types, but not so much reduced as in the hyænas, where they are 
but four on all the feet. In spite of the intermediate position 
of the Canidæ in general structure, they display superiority to all 
_ of the other families in the character of the brain. There are four . 
_ longitudinal convolutions of the cerebral hemispheres, while the 
_ other families have but three; though in some of them (civets, 
Cats), the inferior (Sylvian) convolution is fissured at the ends! 
is character of the dogs is in some degree parallel to that of 
man, whose great brain superiority is associated with general in- 
ae feriority in the osseous and digestive systems. oy, 
sors The range of variation in the family Canidæ, is found in th 
-Nambe 
r of the tubercular teeth, and of the tubercles of the sec- 
: _. ‘riak, and in an occasional reduction in the number of the pre- 
o For the charac 
~ 1882, p. 471, 
VOL. XVIL —N0. ui. 
ters of the families of Carnivora, see Proceed. Amer. Philos. Soc., 
a7 
