MARATTIACEAE 521 
are surrounded by a rather delicate common wall, about four layers of 
cells in thickness, of uniform structure, and without trace of any annulus. 
Centrally there is a vascular strand connected with the system of the 
leaf. ‘The dehiscence appears to have been by terminal pores. The 
number of spores in a single sporangium was very large: to judge from 
Renault’s detailed drawings it was probably equal to the output of the 
modern Kaudfussia (Fig. 288). It is evident that the correspondence with 
this genus was very close indeed: the plan of the sorus is the same: 
its form also, for the terminal depression in Kau/fussia is often less 
marked than is represented in the drawings usually quoted. The two 
are alike also in the thin parenchymatous tissue of the sporangial wall: 
in the absence of any indurated annulus, and in the presence of a 
vascular connection, which I have shown to extend in KXawulfussia also, 
upwards into the receptacle:! though it is not so long or so coherent 
a strand in the living Fern as in the fossil. The differences are of degree 
only, and the similarities are most convincing.? 
Another genus which conforms in type of its fructification to modern 
Marattiaceae is Scolecopteris. This genus includes plants with sessile or 
shortly pedunculate sori, of three to six sporangia: they are united 
below, but separate above, and extended into a more or less elongated 
beak (Fig. 289 pb). The Marattiaceous characters of this fructification 
are unmistakable, and it has been pointed out by Strasburger® that 
Scolecopterts elegans, Zenk, shows features connecting it with Marattia as 
regards the form of the sporangia, and with Xawd/fussia in their circular 
disposition in the sorus, while the outline of their upper free portion 
would point to Azgiopieris: in dehiscence it compares with all three, 
but especially with Marattia. In fact it is a type which unites in itself 
characters of various living genera. It may be noted that the number 
of sporangia in the sorus of Scolecopteris is small and variable, but that 
four and five seem to be the most frequent numbers. 
A genus of very early occurrence, and bearing sori of similar 
character is Asterotheca: here the threé to eight sporangia are in close 
apposition while young almost up to the apex, but they separate 
and diverge radially when mature: the peripheral wall is strongly 
convex, and shows no annulus: the mode of dehiscence was by radial 
slits (Fig. 289 F). 
1 Studies, iii., Fig. 42, p. 46. 
2Mr. D. M. S. Watson (Journ. R. Micr. Soc., 1906, p. 1) has described a ‘‘ Fern” 
synangium from the Lower Coal Measures, well preserved, but detached from the part 
which bore it. It resembles Ptychocarpus unztus in its synangial state, but differs in its 
more elongated form, its hollowed apex, and in the vascular supply being widened into 
a cup of tracheides: in these latter characters it resembles Kaulfussia. There is no 
evidence to show whether it was truly Filicinean or Cycadofilicinean. It is named 
Cyathotrachus altus. 
8 Jenaische Zeitschrift, 1874, p. 87. 
