636 
Proceedings of the Roycd Society 
The sternum was a massive, plate-like, triangular-shaped bone, 
greatly expanded anteriorly in its transverse diameter, and grad¬ 
ually tapering backwards to a rounded apex posteriorly. Inferior 
surface, convex ; superior, concave; anterior border, convex ; lateral 
borders varied in thickness, but were from four to five inches in 
diameter at the thickest part. Four well-marked costal articular 
surfaces on each lateral border. An oval hole, 6^- inches long, was 
in the middle of the manubrial element of the bone, and 4^- inches 
Fig. 2. 
Inferior surface of the sternum of the Skye sperm-whale. 
further back a much smaller foramen pierced the entire thickness 
of the bone. From this smaller hole a mesial and two lateral 
grooves passed for some inches backwards along the inferior surface 
of the bone. On the inferior surface there was no indication of the 
original transverse segmentation ; on the superior surface, 19 inches 
in front of the posterior end, a deep transverse fissure passed across 
the bone through the middle of the third pair of costal articular 
facets, but there was no trace of the original division between the 
first and second segments. 
Extreme length of sternum, 50 inches; transverse diameter at 
