AMERICAN NATURALIST 
Vor. XXVIII. October, 1894. 334 
THE CLASSIFICATION OF SNAKES. 
By E. D. Cort. 
Owing to the absence of limbs and other points in which 
diversity is usually apparent, the classification of the snakes 
has always presented difficulties to the zoologist. An order 
which dates from Cretaceous time and has spread over the en- 
tire world, must have differentiated in structure, if its history 
has been like that of other orders of Vertebrata. Yet the re- 
searches of anatomists have only resulted in finding characters 
which define five suborders, and about a dozen families. Of 
the natural groups thus defined, one family, the Colubridæ, 
embraces three-fourths of the species, and is of cosmopolitan 
distribution. So long as this was the principal result attained, 
it remained clear that the stronghold of the order had not yet 
been taken. 
The primary divisions above referred to, are defined by 
peculiarities of the skeleton, and these were mostly originally 
described by Johannes Müller. In the preparation of their 
Herpetologie Générale, Duméril and Bibron made a full study 
of the dentition. The results they obtained were important, 
but they were very far from expressing an exact and clear eut 
classification. The greatest defect of their definitions based on 
the teeth is that they too often fail to define. One type passes 
by easy gradations into another, so that in many cases it isim- 
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