572 
Mr. De la Beche and Mr. Conybeare on 
We have not yet been fortunate enough to find a specimen which 
would permit us to examine the bones of the hinder and inferior 
portions of the skull ; but the osteological details we have already 
submitted must be considered as placing in the fullest light of de- 
monstration the near alliance of this animal, and its almost identical 
structure, with the crocodile. 
The eye of this animal has its sclerotica, as is well known, com- 
posed of a long or rather scaly substance subdivided into thirteen 
plates. I have now before me the eye of a middle sized lizard from 
Germany, which has a structure exactly similar, excepting that the 
plates are more numerous.* The chamelion, iguana, and tupinam- 
bis, have similar osseous laminae, as has the tortoise, but in this 
latter animal they form, as in birds, the anterior disk. 
A fossil animal found at Milenhart, near Dettingen, in the district 
of Manheim, and described in the Munich transactions under the 
name Lacerta gigantea, which closely resembles, if it be not iden- 
tical with, the Maestricht animal, has evidently the same structure. 
Vertebra . 
Although throughout the bones of the head, so close an analogy 
has been found to prevail between the Ichthyosaurus and Crocodile, 
the vertebras are widely different, and much more analogous to 
those of fishes, having, like them, in consequence of the double 
concave form of their bodies, the inter-vertebral joint deeply cupped 
* This was pointed out to me by Mr. Miller, to whose assistance I have other- 
wise been much indebted, and who by the scientific spirit and unwearied perseverance 
which he has applied to the illustration of the comparative anatomy of organic remains, 
promises to accomplish many interesting discoveries in that branch. His work on 
Encrinital remains, when submitted to the public, will form a model of sagacious, 
patient, anc. successful research. 
