20 
Dinosauria — Iguanodon. 
Hylaeosau 
rus. 
Folacan- 
tlms. 
Wall-case, 
No. 4. 
Table-case, 
No. 7- 
Hypsi- 
lophodon. 
Table-cases, 
Nos. 9 and 
10 . 
Small Glass- 
case, y. 
Iguanodon 
UTantelli. 
Wall-cases, 
Nos. 5 and 6, 
and Table- 
case No. 8. 
The long dermal spines of Ily Iceosaurus, another ai met 
Dinosaur from the Wealden, were arranged in a single row along 
the central line of the back. 
The Polacanthus , or many-spined Dinosaur, from the Weal- 
den formation near Brixton, Isle of Wight, appears, as i egai c s 
its dermal covering, to have been one of the most heavi y- 
armed of these old dragons. Its body was protected by a senes 
of long, laterally-compressed, and more or less acutely triangu- 
lar osseous spines, and also by numerous plain and kee e 
scutes ; whilst the pelvic region was covered by a large shield 
or carapace of thick bone firmly united to the vertebrae and 
ribs, like the carapace in a turtle. The tail was also protected 
by strong bony dermal scutes. 
Many of the limb-bones and vertebrae of the back and tail 
were found associated with the spines, but no remains of the 
neck or head. 
The bases of the spines are broad and asymmetrical, show- 
ing that they were arranged in one or more rows on eithei side 
of the central line of the back. The largest of these spines 
exhibited measures ten inches in breadth, and in height thirteen 
inches. . 
We are mainly indebted to the researches of Prof. Huxley 
and Mr. J. W. Hulke for a knowledge of Hypsilophodon Foxii, 
a small Dinosaur from the Wealden, about 4 feet in length. 
The animal has four large and powerful digits to the hind 
foot, and a small rudimentary fifth outer toe; an extremely 
small fore foot (or mantis'), with four digits and a filth rudi- 
mentary one. The sharp-pointed and curved ungual phalanges 
indicate that it was probably arboreal and rock-climbing in 
its habits. The sides of the crowns of the teeth are finely- 
serrated, and repeat in miniature the serrations of the crown 
of the teeth of Iguanodon. Hyjpsilophodon was destitute of any 
dermal armour. Remains of parts of several individuals have 
been met with at Brixton, in the Isle of Wight. 
“ Mantell’s Iguanodon.” — This is one of the largest of the 
great extinct land-reptiles, some of which certainly rivalled the 
elephant in bulk.* The femur (thigh bone) alone measured 4 
to 5 feet in length. The fore-limbs were very short, so that it 
is almost certain that it did not make use of them constantly 
for progression on the ground, but could readily raise itself into 
an upright position, the weight of its body being countei- 
balanced by its long and ponderous tail, although it was far too 
bulky to progress by leaping, after the manner of a kangaroo. 
The slab in the centre of Case 6 contains a great portion of the 
* As many as twenty-four of these huge Iguanodons were recently obtained 
from the Wealden of Belgium, and three or four almost complete skeletons 
have been put together in the Brussels Museum, proving that they were 
more than 30 feet in length. 
