36 
forward and upward, to the upper end of the front border, it out- 
wardly overlaps the pterygoid, the amount of overlap being greatest 
toward the front and back diminishing to a simple narrow contact at the 
midlength of the overlap. The bone thickens near the maxillary suture, 
and is strengthened interno-anteriorly by a smooth ridge which beginning 
as a thickening of the anterior emargination passes down to the lower 
border. Behind this ridge the inner surface is broadly and shallowly 
concave. In advance of the ridge the bone bends outward and spreads 
transversely to form the jugal surface of contact. In the foremost part 
of its contact with the maxilla the palatine extends downward to some 
extent on the outer surface of the maxillary border. Infero-posteriorly 
the palatine develops a thin, laterally compressed, backwardly directed 
process between which and the main termination of the bone the border 
of the pterygoid ascends to its lapping contact with the palatine. Antero- 
superiorly the palatine apparently does not reach the vomer, the pterygoid 
intervening. 
Mm. 
Maximum height of right palatine 134 
Maximum length of same, measured horizontally within vertical lines, about 185 
Ectopterygoid. (Ept.). Figures 13 and 19. This bone is closely 
applied externally to the maxilla and pterygoid with its length in an 
antero-posterior direction. It is about twdce as long as high and is thin 
and overlapping except in a small in- 
wardly thickened area which fits into 
the postero-maxillary notch, and comes 
between the maxilla and pterygoid in 
sutural contact with both. In lateral 
outline it is broadest behind, narrows 
rapidly forward for one-third of its 
length, and is continued narrowly for- 
ward to its anterior end. Its external 
surface is gently undulating. Its ante- 
rior two-thirds of length lies closely in 
the postero-external concave area of the 
maxilla on and above the shelf formed by 
the horizontal ridge extending back from 
the maxillo-jugal surface of contact. The 
upper and lower borders of the bone, 
where it begins to broaden posteriorly, 
fit into two grooves in the maxillary, 
one in the lower surface of the postero- 
maxillary process, the other curving downward round the posterior end 
of the maxillary ridge. Here the bone thickens inwardly below the superior 
border and fills the maxillary notch, underlapping also the maxillary 
process internally to a slight extent. Below the thickened part the inner 
face of the bone is excavated to fit closely over the upper convexity of 
the posterior end of the maxillaiy. Posteriorly the bone broadly overlaps 
the pterygoid. 
Figure 19. Left ectopterygoid of Edmon- 
tosaurus, Cat. No. 2289; y natural size. 
A, outer aspect; B, inner aspect; mx, surface 
of contact with maxillary; pt, with ptery- 
goid. 
