494 



I 



2817. The germ of a fourth molar, consisting of twelve plates, the first five of which 

 have become confluent at their base. Hunterian. 



2818. The left ramus of the lower jaw, with the inner alveolar wall removed, to show 

 the fourth molar in place and use, and the germ of the fifth in its formative 

 alveolus. 



Of the fourth molar ten plates remain, and all but the last have been in use. The long and 

 slender anterior fang is exposed. The length of this tooth is 5 niches 6 hues. The plates 

 are thicker than in the third molar, in No. 2815. The length of the ramus is 20 inches. 



Hunterian. 



2819. A fourth molar, from the right ramus of the lower jaw. 



It consists of fourteen plates, twelve of which have been in use, and the first, which is worn 

 to the root, may have been the common supporting base of two plates. The length of this 

 molar is 6 inches 4 lines ; its greatest depth is 4 inches 3 lines : but the fangs have not been 

 developed from the hinder part of the tooth. 



Mm. Brit. 



2820. The remains of the fourth molar, from the right side of the lower jaw. 



It has been reduced to the eight posterior plates which are supported upon very long fangs ; 

 the greatest depth of the tooth being 6 inches 3 lines. 



Hunterian. 



2821. The left ramus of the lower jaw, with the fifth molar in its most complete 

 state, the remnant of the alveolus of the fourth molar, and the commencing 

 formative socket of the sixth molar : these are all exposed by the removal of 

 the inner parietes of the sockets. 



The fifth molar consists of fifteen plates, twelve of which have been in use, and the first six 

 are supported on two distinct fangs. The length of this molar is 8 inches ; its greatest depth 

 anteriorly is 5 inches 6 lines. The length of the ramus is 19 inches 6 lines. 



Hunterian. 



2822. The fifth molar, right side, lower jaw. 



It is reduced to its twelve posterior plates, all of which have come into use. The common 

 dentinal base of some worn-down anterior plates is supported on two slender roots, and the 

 fore and inner part of the radical base of the rest of the molar has developed several similar 

 distinct roots. The length of this tooth is 8 inches 6 lines ; its greatest depth is 6 inches. 



Presented by Dr. Henderson. 



