533 



3167. A transverse slice from the crown of the large anterior premolar, upper jaw, 

 of a Horse. Presented by Sir Everard Home, Bart., V.P.R.S. 



3168. A portion of a transverse slice of the corresponding tooth of the lower jaw. 



Presented by Sir Everard Home, Bart., Y.P.R.S. 



3169. A transverse slice from a middle upper grinder of a Horse. 



Presented by Sir Everard Home, Bart., V.P.R.S. 



3170. The moiety of a longitudinally bisected lower molar of a Horse, from the 

 crown of which an oblique section has been removed. 



The cut surfaces have been polished, showing the interblending of the three constituents 



of a compound tooth, viz, the dentine, the enamel, and the cement. 



Hunterian. 



The following specimens, to No. 3175 inclusive, exemplify malformation or disease, attend- 

 ant on aberrations in the dentition of the Horse (Equus CabaUwi) : 



3171. Sections of the skull of a Horse, including the dental series of the lower jaw 

 and portions of the upper jaw, including the last molar tooth. 



The lower jaw presents the rare anomaly of a supernumerary true molar in each rainus, 

 behind the normal third molar, which is characterized, as usual, by the posterior accessory 

 lobe. The supernumerary pair, having no homotypes in the upper jaw, have played ob- 

 liquely upon the back part of the third true molars hi that jaw, and project so far above the 

 normal series as to have occasioned ulceration and absorption in the opposite part of the 

 upper jaw. 



Purchased. 



3172. The skull of a Horse, in which the molar teeth of the left side, in consequence 

 of imperfect apposition, arising from slight distortion of the left ramus, have 

 worn each other obliquely to almost trenchant edges, and are unusually pro- 

 truded from their sockets. Hunterian. 



3173. The anterior half of a transversely bisected skull of a Horse. 



The maxillo-premaxillary sutures have begun to be obliterated at their lower part. The 

 last premolar of the right side of the lower jaw, and its socket, are diseased. 



Purchased. 



