47 
jaw. The first five or six rows are prominently ornamented (Figure 12 B). 
Although they cannot be actually counted, because of the overlying sheet 
of bone, it is quite apparent that there could not be more than three fully 
developed teeth in any one vertical series. On the cutting edge there are 
usually three teeth of the same vertical series present in various stages of 
wear, rarely four. In the maxillary, there are one and two, alternating, 
and rarely, if at all, there are three. Toward the ends these numbers are 
reduced to two and then one. The enamel faces of the nonfunctional 
teeth of the dentary have a vertical diameter nearly three and one-half 
times their greatest breadth. In this as in many other respects they are 
very close to the teeth of the helmet-crested Hypacrosaurus from the 
Edmonton. So far as known it appears that all members of the Lambeo- 
saurinse have the teeth relatively long in relation to their breadth, and that 
in Cheneosaurus they have reached their maximum specialization in this 
respect. They certainly furnish a striking contrast to the short, somewhat 
diamond-shaped, teeth of Thespesius annectens (Marsh). 
The maxillary has 39 vertical rows of teeth in its magazine, and the 
median keel appears to be relatively higher at the basal portion than in the 
dentary series. The outer enamelled faces of the teeth do not combine 
to form a continuous fluted surface as in the dentary, but present a rather 
irregular row of crowns in which the less protrudent teeth are seen, very 
narrow, and the fully functional ones very wide. 
Comparative Measurements of Skulls 
Skull 
Lambeosaurus 
lambei. 
No. 2869, 
G.S.C. 
Lambeosaurus 
lambei. 
No. 351, 
G.S.C. 
Lambeosaurus 
lambei, 
No. 8502, 
G.S.C. 
Mm. 
Mm. 
Mm. 
Greatest length between perpendiculars 
693 
Greatest length from tip of beak to terminal end of 
crest 
822 
Greatest length from tip of beak to posterior border of 
squamosal 
G91 
777 
GOO 
Greatest depth, top of crest to lower border of dent ary 
610 
660 
478 
Greatest height of crest above orbital rim 
302 
307 
193 
Greatest width of premaxillaries at beak 
136 
180 
1001 
“ length of quadrate 
251 
292 
225 
“ “ maxilla 
284 
330 1 
“ u dental series 
253 
300i 
Number of vertical rows of teeth in maxillary 
Lower Jaw 
40 
Greatest length over all with predentary 
565 
654i 
495 
“ “ of dentary 
440 
470* 
373 • 
“ “ from last tooth to tip, anterior 
edentulous portion 
165 
165 
140 
Greatest depth of dentary at centre to alveolar 
border 
88 
91 
75 
Greatest length of dental series 
264 
300 
Number of vertical rows of teeth 
41 
40 
35 
Average length of median nonfunctional teeth 
35 
Estimated. 
68675 — 4 1 
