iI) 
ro) BALAENODON, 
CETACEA. BALAENODON. 
Fig. 226. 
Portion of fossil tooth of Baleenodon, Red-Crag, Felixstow. Nat. size. 
BALAZENODON PHYSALOIDES.  Cachalot-like 
Balaenodon.* 
Tue fossil above figured was submitted to me by Mr. 
Bowerbank, in the year 1840, with a request that I would 
endeavour to ascertain its real nature; and having ob- 
tained the permission of its owner, Mr. Brown of Stan- 
way, to take a section from it for microscopical ex- 
amination, I found by this insight into its intimate struc- 
ture, that it was a fossil tooth, belonging to a Mammalian 
animal; and in that class, bearing the nearest resemblance 
in the thickness and structure of the outer layer of cement 
immediately surrounding the dentine, to the teeth of the 
Cachalot (Physeter macrocephalus). 
The most obvious distinction was, that, great as is the 
thickness of the outer coat of cement in the Cachalot, 
(fig. 218, ¢,) it was still greater in the fossil, (fig. 219, ¢,) 
* Ziphius, generic name of a fossil Cetacean, and édous, a tooth. 
