a new Fossil Animal • 
563 
instance, cannot be said as yet to have been in any degree elucidated; 
the analogies by which its place in the natural kingdom must be 
determined, though ably pointed out, are far from having been 
fully unfolded, and a precise anatomical description of its general 
structure remains a desideratum. 
The great subsequent accumulation of materials, which must 
be doubtless in a great measure attributed to the researches above 
alluded to, and more especially the numerous specimens contained 
in the many collections of this neighbourhood (Bristol) and in that 
of Mr. De la Beche, have afforded me, through the able assistance 
of that gentleman, the means of filling up the most material of the 
chasms in our information on the subjects which I have mentioned; 
and since the points determined are at once in themselves of con- 
siderable importance, and promise, from the analogies above stated, 
to afford considerable assistance in prosecuting our farther obser- 
vations on the newly discovered animal, we shall preface the details 
concerning it, which we are about to submit to the Society, by a 
general and comparative view of the osteology of the Ichthyosaurus, 
ICHTHYOSAURUS. 
General characters . A marine quadruped, nearly resembling the 
crocodile, in the osteology of its head, and its mode of dentition. 
Vertebras having both faces of their body deeply concave as in fishes. 
Extremities having no distinct radius and ulna, but the humerus 
immediately supporting a very numerous series of small polygonal 
bones, forming a very flexible paddle. Anterior extremities much 
larger than the posterior. 
We have retained in these observations the name Ichthyosaurus, 
originally applied to this animal by Mr. Konig of the British 
Museum, feeling convinced that on a full and careful review of its 
