156 Prof. O. C. Marsh—Restoration of Dinosaurs. 
ribs. The first and second caudals have no chevrons. Behind these, 
thee hevron bones are very long, indicating a powerful compressed 
tail, well adapted for swimming. 
In the median dorsal region, between the ribs and the neural 
spines, are numerous rod-like ossified tendons, which increase in 
number in the sacral region and along the base of the tail, and then 
gradually diminish, in number and size, ending at about the thirty- 
fifth caudal. These ossified tendons are well shown in the restora- 
tion, and are of much interest. They are not unlike those in 
Iguanodon described by Dollo, but as a rule are more elongate, and, 
appear to lack the definite arrangement in rhomboidal figures ob- 
served in that genus. 
The fore limbs are unusually small in comparison with the 
posterior, and the relative size of the two is shown in the restoration. 
‘The scapular arch presents many points of interest. The scapular 
is large, and much curved. On the anterior margin, above the 
articulation for the coracoid, is a strong protuberance, with a well- 
defined facet, adapted to the support of a clavicle, if such a bone 
‘were present. The coracoid is very small, and is perforated by a 
Jarge foramen. The two peculiar bones now generally regarded as 
belonging to the sternum were not codssified. 
The humerus is comparatively short. The radius and ulna are 
much elongated, the latter being longer than the humerus, and the 
radius about the same length. The ulna has a prominent olecranon 
‘process, and is a stouter bone than the radius. The carpal bones 
were quite short, and appear to have been only imperfectly ossified. 
The fore foot, or manus, was very long, and contained three functional 
digits only. The first digit was rudimentary, the second and third 
were nearly equal in length, the fourth was shorter and less developed, 
and the fifth entirely wanting, as shown in Plate VII. 
In the functional digits (Plates II. IIT. IV.), the phalanges are 
elongate, thus materially lengthening the fore foot. The terminal 
phalanges of these digits are broad and flat, showing that they were 
-covered with hoofs, and not with claws. The limb as a whole 
was thus adapted to locomotion or support, and not at all for 
prehension, although this might have been expected from its small 
‘size and position. 
The elongation of the fore-arm and manus is a peculiar feature, 
especially when taken in connection with the ungulate phalanges. 
It may, perhaps, be explained by supposing that the animal gradually 
assumed a more erect position until it became essentially a biped, 
while the fore limbs retained in a measure their primitive function, 
‘and did not become prehensile, as was the case in some allied forms. 
The pelvis has already been described by the writer. Its most 
notable features are seen in the pubis and ischium, the former 
having a very large expanded prepubis with the postpubis rudimen- 
tary, while the shaft of the ischium is greatly elongated. 
The femur is long, and the shaft nearly straight. The great 
trochanter is well developed, while the third trochanter is large and 
near the middle of the shaft. The external condyle of the distal 
