ARTICLE VIII. 
OBSERVATIONS ON THE EXTINCT PECCARY OF NORTH AMERICA; BEING A SEQUEI 
TO “A MEMOIR ON THE EXTINCT DICOTYLIN® OF AMERICA.” 
BY JOSEPH LEIDY, M. D. 
[Read November 21, 1856.] 
In attempting to determine extinct animals from a few remains, we are frequently per- 
plexed to know whether one or more species of a genus or of several genera are indicated. 
Were specific characters unvarying, which perhaps could not be the case, the difficulty 
though lessened would not be removed, for recent animals exhibit the fact, that while 
many species are well characterized by external marks, they are not so by the dentition 
and skeleton. \ 
At the period of publishing “A Memoir on the Extinct Dicotylinee of America,” in the 
Transactions of this society, (Vol. X., p. 823,) feeling dissatisfied with the results, I de- 
termined to reinvestigate the subject, which having done, with the aid of additional ma- 
terial both recent and fossil, I have come to the conclusion that all the Dicotyline ani- 
mals supposed to be indicated by the fossil remains, described in the memoir just mentioned, 
really belong to one species of Peccary. 
In comparing a considerable number of skulls of the recent Dicotyles turquatus, I find 
that variations occur equal in value to the characters upon which the different Dicotyline 
genera and species have been proposed by Dr. Le Conte and myself. 
Notice of variations in the skull of the recent Dicotyles torquatus—The skull of Dicotyles 
torquatus varies considerably in size; the smallest and largest adult specimens observed 
differing more than an inch in length. It also varies in the breadth and convexity of the 
forehead; in the length and thickness of the parietal crest; in the width and prolongation 
of the face; in the degree of extension forward of the malar ridge; in the concavity of the 
malar bones; in the extent of inversion of the angle of the lower jaw; the breadth of the 
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