446 



2458. A caudal vertebra of the same Physeter. 



Presented by Sir William Blizard, F.R.S. 



2459. Two ribs of the Cachalot (Physeter macrocephalus}. 



Presented by Sir Anthony Carlisle, F.R.S. 



2460. The left pelvic bone (ischium) of a Cachalot (Physeter macrocephalus}. 



Presented by the Very Rev. Dr. Auckland, F.R.S. 



2461. A tooth of the Cachalot (Physeter macrocephalus), the crown of which has 

 been removed by a transverse section. Hunterian. 



2462. One moiety of a vertically bisected tooth of a Cachalot (Physeter macrocepha- 

 lus}. The cut surface has been polished. Hunterian. 



2463. One moiety of a vertically bisected tooth of a Cachalot (Physeter macrocepha- 

 lus}. Hunterian. 



2464. A tooth of the Cachalot (Physeter macrocephalus}. Mus. Brit. 



2465. A tooth of the Cachalot (Physeter macrocephalus}, vertically bisected, and the 

 cut surfaces of one moiety polished. 



These sections show the teeth of the Cachalot to consist of a hollow cone of dentine, 

 thickly coated by cement, and more or less filled by the ossified pulp. The cement is thickest 

 at the junction of the crown and base, which are not divided by a neck. The laminated 

 appearance of the dentine on the polished surface of these sections is due to a microscopic 

 structure described in Owen's ' Odontography,' vol. i. pp. 355-357. 



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



2466. A tooth of the Cachalot (Physeter macrocephalus}. Hunterian. 



2467. A tooth of the Cachalot (Physeter macrocephalus}. Hunterian. 



2468. A tooth of the Cachalot (Physeter macrocephalus}. Mus. Brit. 



2469. A tooth of the Cachalot (Physeter macrocephalus). Mus. Brit. 



