20 
FOSSIL REPTILIA OF THE 
length of the leg (' cnemion’) is 1 foot; the length of the thigh is 1 foot 4 inches; 
consequently the total length of the hind limb is 3 feet 5 inches ; and, allowing for 
the hbro-cartilaginoiis matter of the joints and the terminal claws, the limb may 
have been 3 feet 8 inches long in the recent animal. 
The femur equals the length of about seven co-articulated dorsal vertebrre, and, 
with the leg, manifests longer proportions to the body than in the Crocodilia ; but 
the foot presents shorter and broader proportions although it has the same number 
of toes. Scelidosanrus, however, differs from Teleosaurus and modern Crocodilia 
in retaining the ungual phalanx of the fourth toe, as in modern lizards (Tab. XI, 
fig. S,iv) ; although it differs from these and resembles the Crocodiles in the non- 
development of the fifth toe. The interesting evidence of this intermediate 
relationship afforded by the bones of the hind foot, as by some other parts of the 
skeleton, is illusHated by the outline figures of the skeleton of the hind foot 
(Tab. XI) in Varanns, fig. 3, in Crocodilus, fig. 4, and as similarly restored in 
Scelidosanrus, fig. 2. 
In the same plate is figured, of half the natural size, the bones of the right 
hind foot of the skeleton of the Scelidosaur wdiich has yielded the subjects of the 
present Monograph ; showing the effects of pressure in fracturing and partially 
dislocating the metatarsal segment, after all the joints of the toes had been 
cemented by the surrounding hardened matrix in their respective varied numbers 
and co-adjustment in each toe. 
Dermo- skeleton. 
The bones belonging to this system were extensively developed in Seelido- 
saurusy and are for the most part of a massive character. They have been much 
displaced in the present specimen, partly during the decomposition of the carcass, 
and partly by subsequent pressure due to movements of the imbedding stratum ; 
but retain their most intelligible natural relations to the endo-skeleton in the caudal 
region : in which part, therefore, I shall begin their description, as they w'ere 
found, on exposing the vertebral characters on the left side, from the end of 
the tail forwards ; and were either removed, or left in situ, as the case required. 
At the thirty-first caudal vertebra, for example, there was attached to the back 
part of the neural arch, and pressed rather obliquely to the left side, an elongated 
triedral dermal bone, with the narrowest side or surface forming the base, and 
the twm broader or larger lateral surfaces converging at an acute angle to an 
upper ridge. Much of this ridge on the fore part of the bone had been broken 
away in the original exposure of the specimen ; the length of what remained was 
1 inch 2 lines, with a basal breadth of 6 lines. The sides of the bone seemed as if 
