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A MANUAL OF DENTAL ANATOMY. 



In the Muridce the decussation of the layers in the inner 

 part, and their parallelism in the outer part of the enamel 



are also found, but in addition to this the borders of the 

 individual prisms are slightly serrated, the serrations of 

 contiguous fibres interlocking. 



In the porcupine suborder the fibres of the inner portion 

 of the enamel pursue a serpentine course, nevertheless 

 showing indications of a division into layers ; they become 

 parallel in the outer portions as in other Rodents. Small 

 interspaces are found amongst the enamel fibres of the 

 Porcupines. 



In the hares (Leporida) the lamelliform arrangement, and 

 the division into outer and inner layers, alike disappear. 



The peculiarities in the disposition of the enamel fibres, 

 which are so marked in the incisors, do not generally exist 

 in the molars of the same species. 



Many minor differences in the arrangement of the enamel 

 prisms exist, for a description of which I must refer the 

 reader to the original paper, but in general terms it may be 

 said that the " enamel lamella) have a different and distinc- 



( ] ) Transverse section of an incisor of a Beaver (Castor fiber). The 

 enamel prisms of superimposed layers cross each other at right angles in 

 the inner portion of the enamel, but all becorce parallel in the outer. 



