7 
maxillae. It makes up much of the side and all of the back of the hood, 
and is flanked infero-laterally by the prefontal and posterior end of the 
lower limb of the premaxilla. 
Figure 1. Cross-section (natural size) of left premaxilla of No. 8676 taken through the 
back of the open slit. L.P. = Lorwer air passage; U.P. = anterior pant of upper air 
passage. 
When viewed from the side the disarticulated nasal (Plate III, figure 1) 
is roughly triangular, with the apex posterior and the anterior edge deeply 
notched. This notch is carried far back on the external surface and 
receives the posterior development of the lower limb of the premaxilla. 
The main body of the bone has thin outer and inner walls with a large 
cavity between. These walls unite interiorly, and give the appearance of 
a thick lower surface, but the bone wall is very thin. The mid portion 
of this inferior surface shows striation for sutural union with the frontal 
and prefrontal, and posterior to this is a rugose area. Anterior to the 
sutural surface a long, decurved, convex process runs forward and down- 
ward to flank the posterior part of the narial passage. Externally it shows 
