... (mandible) is one continuous bone in the mammal. Three incisors bite against the three of the upper jaw. Then comes a canine, four premolars, and three molars, the first of which is blade-like (sectorial tooth), and bites against the similar sectorial tooth (last premolar) of the upper jaw. The third molar is small. The arrangement of tooth is indicated in the following dental formula:— I. 3.3/3.3, C. 1.1/1.1, P.M. ... — Text Book of Biology, Part 1: Vertebrata • H. G. Wells
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