764 MR. D. M. S. WATSON ON 
centrum equally (text-fig. 10). The later dorsals have centra like 
those of the anterior vertebre, but the rib-facet is high up and 
near the front border. The arches are high and massiveand carry 
long transverse processes directed nearly horizontally. The zyga- 
pophysial articulations are flat and inclined to one another and 
the spines not very high. 
The sacrum of Phocosaurus is composed of four vertebrae whose 
centra are fused. The sacral ribs are articulated with both 
centrum and arch; those of the anterior two vertebre are very 
massive and of about the same size, the other two are much 
smaller. One interesting feature is that the distal ends of the 
anterior sacral ribs meet and fuse before they reach the ilium. 
Text-figure 12. 
Right humerus of the type of Pnigalion oweni, X +. 
The caudal vertebre are very short, and the series belonging to 
the type of Tapinocephalus seems to taper rapidly, so that the 
tail was undoubtedly short. 
The shoulder-girdle of Tapinocephaloids seems to be very large 
and massive in comparison with the skull. 
The scapula (Sc., text-fig. 11) is represented by its well-preserved 
lower and upper ends in Phocosaurus and by an isolated bone 
which gives the length. It has a flat blade with no indication of 
an acromial process. The lower end has a long, straight face for 
