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A MANUAL OF DENTAL ANATOMY. 



which is a very large tooth, somewhat triangular in section, 

 with a sharp edge directed backwards, and with a deep 

 groove on its anterior surface. 



The upper premolars are implanted by three distinct 

 roots, as arc also the true molars ; the latter are quadri- 

 cuspid, but lack the oblique ridge. 



Neil, Size , 



The lower canine is a sharp and powerful tooth, though 

 it is very much smaller than the upper; the first lower 

 premolar, by its front surface, articulates with the upper 

 canine, and is of curious form. It is implanted by two 

 roots, but the anterior root is produced forwards, so that the 

 antero-posterior extent of the tooth is much increased. 



The apex of the cusp of the tooth is almost over the 

 posterior root, and from this point the crown of the tooth 

 slopes obliquely forwards down to its anterior root. This 

 peculiarity in the form of the first lower preniolar is eminently 



0) Upper and lower teeth of a Monkey (Macacus nemestrinus, male). 

 The length and sharpness of the canines, and the peculiar form of the 

 anterior lower preniolar, contrasts with the aspect of the corresponding 

 teeth in the Anthropoid Apes or in Man. 



