GALLERY.] 
NATURAL HISTORY. 
183 
elaterite or elastic bitumen of Derbyshire, (a suite of speci¬ 
mens exhibiting all degrees of solidity, from that of honey 
to that of a compact ligneous substance); with these is 
also placed the dapeche, an inflammable fossil substance 
found by Humboldt in South America, having several 
properties of the common caoutchouc or Indian rubber;— 
the hatcliettine , a bituminous substance from Merthyr 
Tydvil in South Wales, the sheererite , &c.—Coal: black 
coal, and brown coal —of these a few specimens only are 
deposited, their different varieties being rather objects for 
a geological collection. 
The collections of Organic Remains begin in Room I. 
with that of the Fossil Vegetables, at present deposited 
chiefly in the Wall Cases of the S. and W. sides of the 
room. A systematic botanical arrangement has been 
adopted, so far as the limited space and the as yet doubtful 
nature of many of those fossil remains admitted of it. 
Case A. is set apart for the yet small number of fossils 
apparently of the class of submerged Alga:, such as the 
Fucoids , Confervites , &c. In the same Case are pro¬ 
visionally placed those impressions on coal slate, of 
plants wuth verticillated leaves, known by the generic 
names of Asterophyllites , Annularia, &c., and supposed 
by some to be referable to the Naiades ; as also a few 
that appear to bear affinity to the Marsilacea:, such as 
Pilularites , Solenites , &c.; together with some other 
vegetable remains, the nature of which is not yet deter¬ 
mined. 
The upper division of Case B. is occupied by the Equl- 
setacea:, most of which may be united under the ge¬ 
neric name of Calamites , the absence of the sheaths by 
which the latter are said to be distinguished from real 
Equiseta, being a character not to be depended upon. 
The species of Calamites , almost all from the rocks of 
the most ancient coal formation, are far from being satis¬ 
factorily determined, their internal structure being en¬ 
tirely unknown. The species of Calamitea of Cotta, (Case 
E.,) which exhibit a peculiar organic structure, can 
scarcely be said to belong to the same natural order. 
The genus Phyllotheca of Brongniart, from the coal sand- 
