23 
heavier than in T. annectens, though this apparent robustness may be due 
to crushing. The form of the obturator processes is obscured by restor- 
ation and their form can no longer be determined. 
The femur is longer than the tibia, the fourth trochanter is strongly 
developed and extends well downward on to the distal half of the shaft. 
The lesser trochanter is separated from the greater trochanter by the usual 
narrow cleft. The greater trochanter rises well above the level of the head. 
Both femora are much flattened by the great pressure to which they have 
been subjected. The tibiae and fibulae are of the usual hadrosaurian type 
and display no distinctive features. The astragulus and calcaneum are 
articulated with the tibia of the right side, but both these bones of the left 
tarsus are missing. 
Parts of the metatarsal bones of both feet are present, but all have 
been so much restored as to be of little value either in showing their relative 
proportions or other characteristics. None of the phalanges can be said 
to pertain to the present specimen, and it is thought all have been either 
restored or supplied from other individuals. 
The principal dimensions of the pelvic and limb bones are given in 
the table of measurements. 
Ossified Tendons 
The preservation of a considerable number of ossified tendons in this 
specimen is of particular interest. Although they are present along both 
sides of the neural spines of the back, sacrum, and tail, only those of the 
left side are now visible, and many of these are covered by the overlying 
skin impressions. Their greatest development apparently is over the 
posterior dorsal, sacral, and anterior caudal regions. Anteriorly they 
extend forward as far as the thirteenth dorsal in front of the sacrum, but 
gradually diminish in number from the sacrum forward. Their diagonal 
lattice-like arrangement is well displayed, and is made up of three layers 
or series, an inner and outer and a deep-seated inner series. The outer 
series is best displayed in Plate IV. Each tendon originates at the base 
of a spine, passes backward and upward across four spines, and is attached 
to the anterior face of the fifth. This was the longest one observed above 
the dorsal region, though there is reason to believe that they become longer 
above the anterior caudal region. The origin of the inner series of tendons 
could not be clearly determined, though they clearly attach on the posterior 
upper face of the spines and pass backward and downward. The deep- 
seated series is only to be observed above the posterior dorsals. 
Each of these tendons is a long, flattened rod with flattened, fabricated 
terminal points which are uppermost; the end of insertion is usually flattened 
but comes to a point. Brown 1 has observed a similar three-layer arrange- 
ment of the tendons in a specimen of Thespesius (No. 5058) in the American 
Museum of Natural History. A skeleton in the Victoria Memorial Museum, 
without head, but evidently pertaining to one of the crested forms, shows 
only two series over the dorsals and sacrals as in Corythosaurus. It would 
appear from this that there was probably a different arrangement of the 
musculature in the two groups: the Hadrosaurinse having three layers 
of tendons over the posterior dorsals and sacrals; the Corythosaurinse 
having only two. 
1 Bull. Am. Mus. Nat. Hist., vol. 38, 1916, p. 713. 
