68 
DEPARTMENT OF BOTANY. 
[upper 
lower fruiting pinnules of which exhibit small bivalved capsules 
like those of the living British Hymenophyllum. Larger specinnens 
of Psaronius from the coal-fields of Ohio occupy the floor of the 
Case. 
The Arborescent Cryptogams of the Palseozoic rocks are repre- 
sented in Case 26. Several specimens of the genus Ulodendron, 
showing the characteristic scars of the aerial roots, are placed on the 
upper shelves ; one of them, U. minus, has the tissues of the vascular 
axis still preserved. On the next shelf are specimens of the stems, 
foliage, and fruit of Galamites, a plant nearly allied to the existing 
Equisetum. Below them, are placed a series of specimens from the 
Devonian Eocks of Gaspe, Canada, presented by Principal Dawson. 
Among them are specimens of the roots, stems, leaves, and fruits of 
his Psilophyton princeps, stems of P. robustius, &c. Here also are two 
specimens of Sigillaria oculata, one of them showing three transverse 
markings produced by seasonal or other interruptions in its growth. 
A section of Sigillaria from the tufaceous rocks of Arran, Scotland, 
enclosing stems of several other plants, all exhibiting the details of 
their structure. A large slab presents a repeatedly branching speci- 
men of Lepidodendron, with leaves attached, from the Halifax coal- 
field, presented by J. Waterhouse, Esq. 
Case 27 contains specimens of Palm Stems, chiefly from Antigua. 
Many of these exhibit the perishable tissues of the plants preserved 
in the most exquisite manner in imperishable silex, and one specimen 
especially shows the delicate leaves of the unopened terminal bud, 
with every detail of the internal structure converted into translucent 
calcedony. 
The fossil Cycadej]: occupy Case 28. On the upper shelf and on 
the floor are placed stems of Mantellia, from the " Dirt-bed " of 
the Isle of Portland, where they are known as Crows' nests." The 
next shelf contains specimens of a remarkable extinct form Bennet- 
tites; two species, B. Saxhyanus and B. Gibsonianus, are from the 
Secondary rocks of the Isle of Wight ; and a ihird, B. Peachianus, 
from those of Sutherlandshire. The details of their fruit are 
exhibited in the transparent sections placed in the Table Case opposite. 
Specimens of one species of Yatesia, from Cambridgeshire, and' three 
from Sutherlandshire, are placed on one of the shelves, and near 
them are a series of Cycadean cones from the Wealden of the Isle of 
Wight. 
Case 29 contains specimens of fossil Conifers. This Order makes 
its appearance early in the rocks of the earth. The Devonian and 
Carboniferous measures contain species belonging to two distinct 
groups, transparent sections of which are placed in the Table Case 
opposite. Two forms of Trigonocarpum from the coal measures, 
believed to belong to Taxineous conifers, are placed in this case. 
Coniferous wood is abundant in Secondary and Tertiary strata, and 
ihere are here specimens from the well-known land surface in the 
Purbecks of the Isle of Portland, from the Cretaceous rocks of Maid- 
