1865.] LOWER JAW IN THE CACHALOT. 393 
bone of the right side, which last is seemingly worn into a groove 
‘by the continued pressure of the left half on it (fig. 26). Internally 
and below, the surface of the latter bulging part of the bone has a 
fibrous appearance, the lines being gently curved round, but in no 
way as if the jaw had been fractured or received a sudden single 
powerful twist. Above the last-mentioned place the surface of the 
bone is roughened and porous in appearance, like what is produced 
by periostitis. The remainder of the bone to the tip is diminished 
in thickness. 
The right half of the inferior maxillary bone has a similar shep- 
Fig. 2. 
Abnormal lower jaw of Catodon (Physeter macrocephalus, Linn.) in the British 
Museum. 
Proc. Zoot. Soc.—1865, No. XXVI. 
