from the Lower Coal Measures of England. 
205 
Comparison of the New Specimens with C. Wedekindi, 
C. LOCULOSUS, AND C. ROBUSTUS, FELIX. 
The dimensions of the various parts have been ascertained by my 
friend, Miss Lockhart, B.Sc., and comparison made with those cited by 
Felix for his forms. It is found that the leaf decreased in thickness from 
the parts where division of the bundles was taking place (Figs. 5 and 6) to 
the parts where division seems to have ceased (Fig. 10). 
The thickness also decreased from the centre to the periphery. The 
margin of the leaf for about a width of 2 millimetres was not more than 
19 ix in thickness. From the data available the whole width cannot have 
been less than 16 mm. — possibly more, but no complete transverse sections 
are available. The thickness ranges from 19 jjl to 88 but Felix reports for 
C. Wedekindi a range from 82 to 99 ju. The space intervening between the 
partitions ranges from 47 \x to 60 fx, whereas Felix reports a range from 55 
to 66 ix. The partitions are seldom less than three fibres in width and often 
show five even in the upper parts of the leaf (Fig. 10, Pa). 
In C. Wedekindi , on the other hand, even where division of the bundle 
is still taking place, the partitions are shown to be comparatively thin. 1 
The bundle sheath in the new species is also relatively better developed 
than in C. Wedekindi. 
In C. Felicis the leaf parenchyma is built up of transversely running 
strands of cells which are slightly elongated in the direction at right angles 
to the bundles. These strands show very narrow crevices between them 
which are exaggerated by the shrinkage of the cells in Fig. 3. The lacunae 
do not show in transverse sections of the leaf, as the sections are thicker 
than the cells or the lacunae. They can be detected with difficulty in 
longitudinal sections taken vertically to the surface between the bundles 
(Fig. 4), but are always clearly seen in horizontal sections (Fig. 3). 
No crystals have been observed, though the cells occasionally show 
blackened contents — a state of preservation which appears to correspond in 
the bundle sheath with an incomplete differentiation of the fibre. 
Thus C. Felicis appears to be a leaf of relatively robuster build than 
C. Wedekindi. It has a much wider range of structure than was attributed 
to C. Wedekindi by Felix — the term being used to include forms which 
somewhat resemble C. loculosus and C. robustus , Felix. The latter, how- 
ever, like the ‘ Wedekindi * form, exceed the basal sections of C. Felicis in size, 
for the section of * C. robustus ' described reaches a thickness of 1 15 [x as 
compared with the 75 [x reached by a section of C. Felicis in what I regard 
as a corresponding plane (Fig. 5). 
1 Felix: loc. cit., PI. Ill, Fig. 4 (the only published figure of this species). 
