4 ARKIV FÓR BOTANIK. BAND 10. w:o 15. 
the same opinion concerning the disposition of the sporangia 
as that expressed below. This specimen and that of the Stock- 
holm Museum form together a fairly well characterized type of 
fertile leaves. It does not appear convenient to retain the wider 
and more provisional name Cladophlebis for these leaves, so I 
have ventured to institute a new genus for their reception. 
They appear to be identical with the Pecopteris undans LINDL. 
& Hurr. and the species should thus be named 
Cladotheca undans Lispr. & Hurt, sp. 
The two specimens which I have examined, agree in all 
essential characters. The Stockholm specimen is figured in pl. 
1, fig. 1. It represents only a fragment of a pinna, 2.5 cm. long 
and 2 em. broad. The pinnules are fairly closely set, attached 
to the rachis by the whole of the base. They measure about 
4 mm. in breadth at the base, are almost linear and are obtusely 
pointed at the apex. The margin is faintly undulating. The 
Specimen represents an impression of the lower side of the 
pinna, and this impression is in places covered by a fairly thick 
carbonaceous layer. On the surface of the coal there are seen 
lines which appear to represent the secondary veins, running 
from the midrib to the margin. They are slightly arched and 
set on to the midrib in the same manner as are secondary veins. 
But these lateral lines are much more marked, appearing mostly 
as distinct grooves which widen towards the margin. This is 
due to the fact that they mark, at the same time, the attachment 
of the sporangia which are placed on the lateral veins, on the 
lower side of the pinnules. It would appear as if the secondary 
veins were simple; but this is not certain, since what is seen is 
not the actual vein but the receptacle bearing the sporangia. 
A branch which bears no sporangia might therefore, if existing, 
be invisible on the surface of the coal. At any rate, no certain 
traces of branching of the veins have been observed. 
The Cambridge specimen (pl. 2, fig. 1) consists of two pin- 
ne, which are attached to the same side of a rachis. The resem- 
blance to the specimen described above is in other respects very 
close. The main difference is that the pinnules are somewhat 
shorter and broader and that the margin is more deeply dentate. 
The pinnules are slightly retreciated near the base — this is es- 
pecially evident in the case of the proximal margin. The vein- 
