GALLERY.] NATURAL HISTORY. 195 
vegetable remains, the nature of which is not yet deter¬ 
mined. 
The upper division of Case 2 is occupied by the Equi- 
setace.®, most of which may be united under the ge¬ 
neric name of Catamites, 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 Catamites, 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 Phytlotheca of Brongniart, from the coal sand¬ 
stone of Port Jackson, in which the sheaths are pro¬ 
longated into leaves, is a distinct genus of this order; 
as is likewise the Equisetum. Lyetlii from Pounceford. 
The lower division of Case 2, and part of 3, contain 
the Ferns (Filices), most of them as impressions in clay 
slate forming the carboniferous strata of the transition 
series. Many of them bear a strong resemblance to exist¬ 
ing, especially tropical, species ; and fructification, dis¬ 
tinctly exhibiting the sporangia variously disposed in sori, 
&c., has latterly been observed in several species; but 
the classification founded on characters derived from them 
and the distribution and ramifications of the nerves, though 
of great importance in the classification of recent ferns, is 
obviously, at least in the present state of our knowledge, 
inapplicable to those in a fossil state. The arrangement 
and the generic names here adopted, with occasional devia¬ 
tion, are those proposed in the concluding numbers of the 
late Count Sternberg’s work. The species, as far as de¬ 
termined, are all named; the synonymy being added in 
most cases where it appeared requisite. 
In the upper division of Case 3, and part of 4 and 5, 
are deposited those genera which are generally supposed to 
belong to the family of Lycopodiacea:, of which Lepido - 
dendron of Sternberg ( Sagenaria of Presl.) is the principal 
one. Much uncertainty still prevails in the determination 
of the genera and species of this family. Some of them 
k 2 
