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and 5 inches across the middle of the shaft. 6. A slightly curved 
portion of a rib, a yard long and from 13 to 2 inches thick. 7. Five 
caudal vertebrz agreeing in dimensions with the vertebrze of Chip- 
‘ping Norton. 
Numerous fragments of long bones without a trace of a medullary 
cavity have been found at Chipping Norton, and correspond in mag- 
nitude with the vertebre. The articular surfaces which are pre- 
served are covered with large tubercles for the attachment of thick 
cartilages. The best preserved fragments are considered to belong 
to metacarpal or metatarsal and phalangeal bones, and are therefore, 
Prof. Owen says, decisive evidence against the cetacean nature of 
the animal; but he adds, they possess characters by which they 
may be distinguished from the corresponding bones of known ex- 
tinct gigantic saurians. One of these bones, believed to be a meta- 
carpal or a metatarsal, is double the bulk of the largest analogous 
bone of a full-grown elephant, though the metacarpals or metatar- 
sals are much smaller in proportion in Saurians than in Pachyderms. 
The bone is 7 inches in length, 9 in circumference in its middle, 5 
in the antero-posterior diameter of its proximal end, and 4 inches 
8 lines in the transverse diameter of the distal end. A proximal 
phalanx is shown to be remarkable for its short and broad propor- 
tions, which are more massive than those of the phalanges of exist- 
ing Crocodilians or of the Poikilopleuron. 
An ungueal phalanx, also found at Chipping Norton, was 6 inches 
in length, 24 in breadth, and upwards of 3 in depth. It was slightly 
curved, obliquely compressed, obtusely terminated with a shallow, 
concave, trochlear articular surface, divided by a vertical convexity ; 
it was marked on each side by a smooth curved groove, 3 inches 
in length, with the concavity downwards, and the lower edge pro- 
Jecting beyond the upper at the posterior part of the groove; but it 
is shown to be by no means produced in so large and thick a ridge 
as that which characterizes each side of the more depressed and 
broader phalanx of the Iguanodon. From the ungueal phalanges of 
that Saurian it differs m being much less compressed from side to 
side and less curved downwards. It vastly surpasses in size any 
of the ungueal phalanges of the Poikilopleuron. A smaller ungueal 
phalanx, resembling in general shape the above, was found at Chip- 
ping Norton; and portions of metacarpal or metatarsal bones, agree- 
ing in form and size with the fragments obtained at Chipping Nor- 
ton, have been discovered at Buckingham: also a fragment 8 inches 
long, which Prof. Owen considers to have belonged to a radius, a 
fibula, or a long distal phalanx. 
With reference to a comparison of the remains of the Cetiosaurus 
with those of the Polyptychodon, the bones of the extremities pre- 
sent in both cases the cancellous structure throughout the central 
part, which indicates aquatic rather than terrestrial habits. Prof. 
Owen states that he has not found any of the remains of the extre- 
mities of the Cetiosaurus to agree exactly in shape with those be-. 
longing to the Polyptychodon; also that no specimen of a tooth 
agreeing in characters with the teeth of the Polyptychodon has been 
detected in secondary strata inferior to the greensand. Certain 
