NATURAL HISTORY. 
75 
GALLERY.] 
*don, chiefly from the strata of Tilgate Forest in Sussex ; a suite, 
which, together with the great group of bones from Maidstone embedded 
in Kentish rag, (in a separate glass Case placed at present under the 
central window,) has furnished Dr. Mantell with highly valuable 
materials for the illustration of that extraordinary reptile, scarcely less 
remarkable in its osteology than the gigantic animal (Wall Case 2) of the 
same order, discovered by that naturalist, and to which he has given the 
name of the Wealden Lizard ( Hylceosaurus ,) to express the circum¬ 
stance of its occurring in the strata of that geological formation. 
In the Wall Cases 4 to 7, of this Room, and in all those of Room 
IV., are arranged the order En altos auria, or Sea Lizards, of the sub¬ 
division of which the genera Plesiosaurus and Ichthyosaurus are the 
principal types. Among the species of the former may be particularized 
the Plesiosaurus Hawkinsii , chiefly from the lias quarries of Street, and 
thus named by Mr. Owen in honour of the author of the work in which 
most of the specimens are figured and described that formed his 
collection, now partly deposited in this Gallery;—the species from Lyme 
Regis, first described by Mi. Conybeare, and named P. dolichodeirus , 
its neck being nearly equal in length to the body and tail united ;—the 
P. rugosus from the lias near Belvoir Castle, presented by H. G. the 
Duke of Rutland, being a unique nearly complete specimen of this 
species;—the specimen of a Plesiosaure, of which an account and figure 
have been given in the Philosophical Transactions for 1719, by Mr. 
Stukeley, who mistook it for a crocodile. 
In and on the Wall Cases of Room IV. are placed the larger speci¬ 
mens of the various species of Ichthyosaurus , or the fish-lizard, so de¬ 
nominated on account of their having in a recent state clearly presented 
the external appearance of certain orders of fishes combined with the 
internal organization belonging to the Saurian reptiles. The most 
striking specimens are the I. Platyodon in the central Case, and various 
bones of its gigantic variety on the top of the same Case and in Case 2, 
such as the head cut transversely to show the internal structure of the 
jaw 7 s; the carpal bones of one of the extremities, &c.: all from the 
lias of Lyme Regis;—a new small species I. latifrons , in which the 
spiracle on the top of the head, between the eyes, claims particular no¬ 
tice, from Balderton in the county of Nottingham, presented by Dr. 
Bland ;—the splendid specimens of P. interrnedius , P. lonchiodon, P. 
communis , all from Lyme Regis; the P. longipinnis and P. longiros- 
tris from Whitby, &c. 
In the central passage between the Table Cases of these Rooms are 
placed various obj ects illustrative of particular mineral substances. One 
of the most interesting is a Table, presented by H. G. the Duke of 
Rutland, the slab of which is composed of a stalagmitical calcareous de¬ 
position, which w 7 as found investing the interior of a square wooden pipe 
in Blythe Lead Mine, Derbyshire. 
In the small Table Cases under the windows of Rooms II. and III. 
are temporarily deposited various mammalian remains, chiefly from the 
caverns of Kirkdake in Yorkshire, and from Kent’s Cavern, Devonshire, 
numerous remains of bears and of other animals from those of Gailen- 
reuth, in Franconia,* &c. 
The Table Cases in the two last rooms are at present occupied by 
various unarranged fossils, such as corallines, sponges, crinoidea, echino- 
E 2 
