BAL^NODON PHYSALOIDES. 



Fig. 229. 



539 



Microscopic structure of cement ; magnified 500 diameters. Dal<enodon. 



cular or medullary canals, few in number, and irregular 

 as compared with those in the thick cement of the Mega- 

 therium's tooth, and more like those in the cement of the 

 Physeter.* 



I have recently received from Professor Henslow the 

 conical termination of the crown of two teeth of Balfenodon, 

 also from the Red Crag at Felixstow, showing the same 

 ferruginous tint, brittle texture, and water-worn surface ; 

 but retaining a shape more plainly ^bespeaking their dental 

 nature. The diameter of the fractured base of the larger 

 conical fragment is two inches ; that of the obtuse apex 

 about two-thirds of an inch : the length of the fragment 

 being four inches ; the tooth tapers more gradually 

 to its summit, and is less curved than in the Cachalot. 

 This fragment has belonged to part of a larger tooth than 

 the one (fig. 226,) first determined, and the diameter of 



* I must refer the Reader to my ' Odontography,' p. 356, pi. Ixxxix, a, for 

 an account of the microscopic structure of the Cachalot's tooth, which may be 

 compared with the account here given of the tooth of Bakenodon. 



