In. gallery.] 
NATURAL HISTORY. 
157 
FIFTH ROOM. 
The Upright Cases round the Room contain the specimens of the 
Molluscous and Radiated Animals preserved in spirits. They are 
arranged as the other specimens in the Table Cases in the Eastern and 
Northern Galleries. 
The Table Cases contains the Sponges, which resemble Corals in 
various particulars, but their animal nature is not distinctly made out; 
those found in collections are merely the skeletons of the living 
mass, entirely destitute of the gelatinous portion which constitutes 
the animal, if it be really of that nature. Some naturalists have con¬ 
sidered these skeletons, or Sponges, as analogous to the stems of Anti- 
pathes f or Black Coral, and consequently to the axes or central supports 
of Zoophytes; and have fancied that, when alive, they were covered, 
like the Antipathes , with a perishable crust, consisting of the dried poly¬ 
pes. But recent observations on them in their living state have not 
verified this theory ; for they have been found to be entirely destitute 
of any polypi, to be mere living masses covered with a gelatinous coat, 
and absorbing water through the small pores spread over their surface, 
and emitting it by the larger scattered holes called oscula; and though 
the fibres of many of the sponges greatly resemble the axes of the Gor- 
gonice in their chemical composition and organic structure, they never¬ 
theless cannot, be confidently pronounced to belong to the animal, 
rather than to the vegetable kingdom. In some, the skeleton, which 
alone can be shewn in the dry state, consists of a horny fibre, ( Spongia ,) 
in others it is formed of interwoven calcareous spiculse, which greatly 
vary in their shape. In a few the spiculse are formed of pure flint, and 
of sufficient hardness to scratch glass. 
The Tethya, (Table 7,) differs from the Sponges with siliceousspiculae 
in being more or less globular, with all the spiculse radiating from the 
centre, and in its outer surface being covered with a crust formed of 
minute calcareous globules. 
/:■ • JOHN EDWARD GRAY. 
June 24, 1842. 
NORTH GALLERY. 
This Gallery, above the Library on the North side of the North Wing, 
is appropriated to the Oryctognostic or Mineralogical Collection, and 
to that of Palaeontology (Secondary Fossils or Organic Remains). 
The greater portion of these Collections, removed from the room here¬ 
tofore called the Long (but now the Eastern Zoological) Gallery, is 
under re-arrangement. According to the plan laid down for their dis¬ 
tribution, the Table Cases containing the General Collection of 
Minerals will form two rows or series, extending through four rooms, 
as follows ;— 
In Room I., being the N. E. corner room, the first series of Table 
Cases begins and the second terminates : it contains Cases 1 to 6 and 
55 to 60. Room II. contains the Cases 7 to 13 and 48 to 54. Room 
III. will contain the Cases 14 to 23 and 38 to 47 ; and Room IV., 
the Cases 24 to 30 and 31 to 37. 
