OF COAL-MEASURE PLANT-IMPRESSIONS. 193 
however, does not appear to be ridged. The most recent figures by Renier 
(1911) are also similar. 
‚Notes on the Examples of L. lycopodioides here figured. 
(The numbers refer to specimens in the Carboniferous Plant Collections, 
Sedgwick Museum, Cambridge.) 
As in other species of Lepidodendron, the leaf bases of this type differ 
greatly in size and shape, according to the age of the branch. 
No. 3205. One of the specimens of this species, with the largest leaf bases 
with which I am acquainted of any from this horizon, is shown, natural size, on 
PI. 10. fig. Land enlarged in fig. 2. This isa specimen from the Middle Coal 
Measures of the Bishopsbourne Boring, Kent, at 2513 ft. The leaf bases 
here measure 145 mm. long by 7 mm. broad. They are much less crushed 
than is usually the case. The lateral angles are rounded, the apex is some- 
what obtuse, and the lower extremity attenuated, st raight or slightly bent. 
The leaf scur is a transverse slit situated very high up. As is so often 
the case in regard to this species, the carbon of the leaf base is extremely 
brittle and is liable to flake off, especially in the neighbourhood of the leaf 
scars. Sometimes the absence of a small triangular piece of carbon in 
this region simulates, and may be mistaken for, a leaf scar. The lateral lines 
arising from the leaf sear are long and extend downwards to or just beyond 
the lateral angles of the base. The keel below the leaf scar is ornamented 
by numerous transverse ridges, especially in the lower part of its course, 
No, 2754. The leaf bases of another specimen from Bond’s Main Colliery, 
Temple Normanton, Derby (Middle Coal Measures), are illustrated on Pl. 10. 
fig. 3, natural size. Here the carbonaceous film has flaked off in the neighbour- 
hood of the scar—a characteristic feature. These leaf bases measure about 
14 mm. in length and 5 mm. in breadth. They are very little compressed, 
and the lateral lines are clear. The keel is faint or absent, and the ornamen- 
tation is slight. | 
No. 107. We pass now to branched examples still bearing some leaves 
attached. Fig. 4, PI. 10, shows the leaf sears of such a specimen from 
Toronley Colliery (coalfield unknown), natural size, and Pl. 10. fig. 5, the 
same enlarged. The leaf bases are here 7 or 7°5 mm. long and about 3 mm. 
across. In most cases they are slightly decorticated by the flaking off of 
the carbon. The lateral lines are clear. The keel is faint, but the ornamen- 
tation consists of round or oval conspicuous projections. 
No. 927. Figs. 6 & 7, Pl. 10, represent a specimen from the Middle Coal 
Measures of Flimby, Cumberland, which has several times been figured. 
The leaf bases here are very broad, quadrate, almost square, measuring 6:5 
x55 mm. The angles are nearly all equal. The leaf scar is almost, if not 
