ROOM III. DERMAL BOXES OF THE HYL^OSAURUS. 



319 



DERMAL BOXES. Elliptical and circular dermal bones, 

 having the under surface flat, and the upper convex with a 

 conical tubercle, were first noticed in this specimen of the 

 Hylceosaurus ; I have since discovered similar scutes asso- 

 ciated with other remains of this extraordinary reptile. (See 

 Lign. 68, figs. 1, 3.) 



LIGX. 



DERMAL BOXES OF REPTILES; FROM TILGATE FOREST. 



Fig. 1, and 3. Dermal scutes of the HYLJEOSATJRUS : not. size. 



la. The under surface of a fragment of a dermal bone, displaying fine 



spicula, decussating each other at right angles, and indicating a 



similar structure to that of the Corium: nat. size. 

 \b. A portion of the same, highly magnified, and viewed by transmitted 



light. 

 2. HORN or DERMAL TUBERCLE, probably of the IGUANODON : i nat. 



size. 

 4. A DORSAL DERMAL SPINE of the HYLJEOSAURUS ; the original is 



thirteen inches long. 



The structure of these scutes is very remarkable ; upon 

 closely inspecting either the under side, or the surface exposed 

 by a transverse fracture, very minute osseous spicula, decus- 

 sating each other at right angles, are distinctly seen. (Lign. 

 68, fig. l a .) In fig. l b , a thin slice of a bone, magnified, and 

 viewed by transmitted light, displays medullary canals, with 

 very fine" lines radiating from them. The peculiar character 



