T^NIODONTA. 191 



well as for cutting purposes. From this ledge the anteroposterior diameter 



is equal throughout. The exposed dentinal pcti-tion is more concave on 



one side than the other, though both are slightly concave. The enamel is 



strongly convex all round, excepting a shallow longitudinal groove on the 



more concave side. Its surface is marked with obsolete parallel ridges. The 



third incisor is a large prismatic tooth of triangular section. The inner 



face, which is applied to the second incisor, is flat, and is the widest. The 



anterior is convex, and is the next in width. The posterior external is a 



little narrower, and is flat. Its enamel has some obsolete longitudinal ridges, 



and several transverse undulations or obsolete ribs. The external face of 



the canine is narrower than that of the third incisor, and is wider than the 



posterior face. Anteriorly there is a faint longitudinal groove and several 



transverse undulations. The posterior face has transverse wrinkles. 



The grinding surfaces of the molars are subquadrate in outline, with 



rounded angles. The posterior three are rather narrower posteriorly than 



anteriorly. They are of about equal size, the first only being a little 



smaller than the others. The roots are conic in this adult specimen. The 



enamel extends well down on the external faces, although concealed in the 



alveolus. This looks as though the tooth enjoyed a considerable period of 



growth before the dentigerous pulp disappeared and the apex of the root 



closed. This is probably true in a more marked degree of the C. cylindri- 



fer. In wearing, the anterior external border of the crown is a little more 



elevated than the i-emainder. 



Measurements. 



M. 



Length of ramus from coudyle to I. ii iucliisive 206 



Length of ramus from condyle to front of base of coronoid process 100 



Length of dental line l:!0 



Length of molar series 080 



„. , .. ,, ..< anteroposterior 0145 



Diameters ot M. ii < *^ 



( transverse 0145 



Diameters of canine ^ ° 



( shorter Oil 



„. . ,. T ..< anteroposterior 021 



Diameters ot 1. iii < ' 



( tr.insverse 010 



T^. . , I c T ••• (transverse 017 



Diameters external face 1. iii < 



( vertical from alveolus 020 



030 



& 



„. . T •• / 4. -i \ ( anteroposterior 

 Diameters I. u (extremity) ^ ' 



. ( anteriorly 016 



transverse ■; ■' 



I posteruuly 010 



Depth of ramus at condyle 0d3 



Depth of ramus at apex of coronoid 115 



