5 
the fork is broken off. The pleurapophysis is as in the fifth, but with a longer and more 
curved hemapophysis, 4 inches in length, and with a rather shorter epipleural lamina. 
In the seventh dorsal the hypapophysis is a compressed subquadrate plate, a little 
expanded at its lower margin. The pleurapophysis, 6 inches in length, retains its 
slenderness ; the hemapophysis is 4 inches 8 lines in length. 
In the eighth dorsal, the hypapophysis is suddenly reduced to a low triangular process. 
The pleurapophysis, 6 inches 3 lines in length, articulates with a hzmapophysis of more 
slender proportions, 5 inches 2 lines in length. 
In the ninth dorsal, the hypapophysis is again represented by a low median ridge. 
The pleurapophysis, 6 inches 6 lines in length, articulates with a hzmapopbysis (h) 
5 inches 6 lines in length ; and this is the last of those that directly articulate with the 
sternum. 
The tenth dorsal becomes, by confluence of its centrum, the first sacral (ib. s), but 
retains its neural spine distinct from, though contiguous with, the long sacral ridge ; its 
pleurapophysis (pl) is 6 inches 2 lines in length, and articulates with a hemapophysis (h) 
5 inches 2 lines in length, the distal end of which is applied to the preceding hamapo- 
physis about one inch from its articular end. 
In the dorsal region, the articular facets of the centrum are simplified to a very slight 
convexity in front and a corresponding concavity behind (PI. II. fig. 7, c). 
The sacrum (PI. I. fig. 1, s), 4 inches 2 lines in length, and including about thirteen 
vertebre, presents at its beginning rather long and narrow centrums; but these expand 
laterally, and subside vertically to the sixth, whence they gradually again contract in 
breadth to the antepenultimate vertebra: the centrums are all confluent. The hinder 
half of the expanded rhomboid portion of the under surface of the sacrum is broadly 
and slightly grooved. 
Transverse processes, from the second to the sixth sacral inclusive, abut against the 
ilia; in the next three vertebrae these processes are scarcely marked ; they reappear in 
the following sacrals, with articular surfaces for the ilia, increasing in vertical extent. 
The first free caudal has also a short thick transverse process, which abuts against the 
ilio-ischial part of the os innominatum. 
The length of the iliac element (PI. I. fig. 1, 62) of this bone is 4 inches 6 lines; its 
extreme breadth, an inch from the fore margin, is 9 lines. That margin is rounded ; 
the outer one is at first convex, then concave, contracting before expanding again, and 
thickening (at 62) to contribute to the acetabulum. The expanded fore part of the 
ilium is a very thin lamella. The acetabulum, widely open, is overtopped by an articular 
facet adapted to the upper part of the neck of the femur. The ilium quickly contracts 
in breadth behind the acetabulum, beyond which it extends nearly 2 inches, as far back as 
the third caudal; it coalesces with the ischium about an inch behind the acetabulum, cir- 
cumscribing an elliptic ischiadic foramen (7) 9 lines in length and 4 lines in short diameter. 
The ischium (63), after the iliac confluence, extends backward as a pointed styloid 
