•204 
MARINE SAURIANS. 
Head.* 
The head of the P. Dolichodeirus exhibits a 
combination of the characters of the Ichthyo- 
saurus, the Crocodile, and the Lizard, but most 
nearly approaches to the latter. It agrees with 
the Ichthyosaurus in the smallness of its nostrils, 
and also in their position near tlie anterior angle 
of the eye ; it resembles the Crocodile, in having 
the teeth lodged in distinct alveoli ; but differs 
from both, in the form and shortness of its head, 
many characters of which approach closely to 
the Iguana.'!' 
feet fossil skeleton, also in the British Museum, discovered by Mr, 
Hawkins, in the lias at Street, near Glastonbury. At PI. 16 is also 
copied Ml. Conybeare s restoration of this animal, from dislocated 
fragments, before any entire skeletons were found. The near 
approach of this restoration to the character of the perfect ske- 
letons, affords a striking example of the sure grounds on which 
comparative anatomy enables us to reconstruct the bodies of fossil 
animals, from a careful combination of insulated parts. The 
soundness of the reasoning of Cuvier, on the fossil (juadrupeds 
of Montmartre, was established by the subsequent discovery of 
skeletons, such as he had conjecturally restored from insulated 
bones. Mr. Conybeare’s restoration of the Plesiosaurus Doli- 
chodeirus, (PI. 16,) was not less fully confirmed by the speci- 
mens above mentioned, 
* See PI. 16, 17, 18. 
•f Mr. Conybeare, in the Geol. Trans, second series, vol. 1> 
part 1, PI. 19, has published figures of the superior and lateral 
view of a nearly perfect head of this animal. Our figure, PI. 18, 
Fig. 2, represents the head of the specimen in the British Mu- 
