22 
EXPLANATION OF PLATE 10. 
6. Front view of bony plates in the Eye of an Iguana. 
7. Profile of the same. 
8. Two of tlie fourteen component scales of the same. 
I owe these three last figures to the kindness of Mr. Allis 
of York. 
A 1, 2, 3, 4. Petrified portions of the skin of a small 
Ichthyosaurus, from the Lias of Barrow on Soar, 
Leicestershire, presented to the Oxford Museum, by 
the Rev. Robert Gutch, of Segrave. (Original.) 
In Fig. 1 ; a, b, c, d, are portions of ribs, and e, f, g, h, 
are frao'ments of sterno-costal bones (nat. size). 
O 
Tlie spaces between these bones, are covered with the 
remains of skin; the Epidermis being represented by a deli- 
cate film, and the Rete mucosum by fine threads of white 
Carbonate of Lime ; beneath these the Corium, or true 
skin, is preserved in the state of dark Carbonate of Lime, 
charged with black volatile matter, of a bituminous and 
oily consistence. 
2. Magnified representation of the Epidermis and Rete 
mucosum. The fine superficial lines represent the 
minute wrinkles of the Epidermis, and the subjacent 
larger decussating lines, the vascular net-work of 
the Rete mucosum. 
In Fig. 3, the Epidermis exhibits a succession of coarser 
and more distant folds or wrinkles, overlying the 
mesh-work of the Rete mucosum. 
In Fig. 4, the Epidermis has perished, and the texture 
of the fine vessels of the Rete mucosum is exhibited 
in strouo- relief, over the black substance of the sub- 
jacent Corium, in the form of a net-work of white 
threads.* 
* Nothing certain has hitherto been known respecting the dermal 
covering of the Ichthyosauri ; it might have been conjectured that 
these reptiles were incased with horny scales, like Lizards, or that 
their skin was set with dermal bones, like those on the back of Cro- 
