184 
NATURAL HISTORY. 
[north 
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 Lyellii from Pounceford. 
The lower division of Case B., and part of C., 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 C., and part of D. and E., 
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 
appear to exhibit an internal structure intermediate be¬ 
tween that of the Lycopodiacae and the Coniferse ; but 
Lepidodendron punctatum of Sternberg, of the unique 
specimen of which, in Mr. Cotta’s collection, a portion is 
seen in CaseC., 6,) presents the organization of a real arbo¬ 
rescent fern. Nearly allied to the Lepidodendra are seve¬ 
ral vegetable fossils, considered as distinct genera, among 
which may be specified Lepidophyllum and Lepidostro- 
bus (Case D.) of Brongniart, (the former perhaps only 
the leaves, the latter the fruits of species of Lepidoden¬ 
dron or Lycopodites,) the Ulodendron ( Lepidod . ornatis - 
simum , Sternb.), the Bothrodendron of Lindley, the Rhyti - 
dolepis of Sternb., &c. 
In the upper division of Case E. are placed the species 
of Sigillaria , (including Favularia ,) Brong., which are very 
distinct in their structure from arborescent Ferns, with 
