1878. } Saurians of the Dakota Beds of Colorado. 77 
very short and wide; but the length of the centra gradually 
increases, so that the distal ones are quite elongate. The caudal 
centra are all moderately amphiccelous. 
| The sacrum is short and consists of only four vertebral centra, 
thoroughly coossified. The anterior articular extremity is convex; 
that of the posterior extremity slightly 
concave. Its transverse processes are 
like those of the other vertebrae, muc 
elevated, although they spring from the 
centra. The external face of their bases 
is not prominent, and the spaces between 
their projecting portions are deeply exca- 
vated. The centra are like those of the 
caudal vertebrz, composed of dense bone. 
The extremities of the adjacent transverse 
processes are united, thus enclosing large 
foramina. 
The scapula is relatively of large size. 
It is rather elongate, and the superior ex- 
tremity is expanded. There is a very 
large mesoscapular process, which is 
wanting in Cetiosaurus, according to Phil- 
lip’s figures. It appears to resemble the 
scapula in Dystropheus.' (See Fig. 10.) 
The coracoid bone is of proportionately 
small size. It is of an irregularly quad- 
Fig. 9——View of the right rate form, with the proximal extremity 
side of the dorsal vertebra of 
Camarasaurussupremus,rep- the shortest. The articular face is large, 
resented in Fig. 5. and is presented obliquely away from 
Pe the long axis of the plate. There are no emarginations nor in- 
_ termediate processes, and the perforating foramen is well removed 
» from the border. 
Pelvic bones of two forms are present. Neither of them 
_ resembles pelvic bones of Dinosauria, and are least of all similar 
to the forms of ilium which are known in that order. One of 
_them is a robust L-shaped bone, one limb of which is expanded 
into a wide fan-shaped plate; and the other is stouter and of sub- 
equal width, terminating in a stout sub-triangular articular 
extremity. 
1See Report Lt. Wheeler, Vol. IV, pl. LX XXIII, p. 31. 
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