would be inappropriate inasmuch as this ‘‘genus”’ in- 
cludes a variety of unrelated fructifications, some of which 
are megasporangia filled with large numbers of spores. 
The sporangium is similar in its construction to Lep- 
idocarpon lomaai Scott, but the tissues developed within 
the sporangium show much more detail than in this spe- 
cies. At the proximal end of this seed-like sporangium 
there is a vascular trace which forks twice, but the four 
branches quickly exhaust themselves. The bifurcations 
are at right angles to each other, and by serial sections it 
has been observed that the two forkings take place one 
above the other. ‘The individual elements in the vascular 
trace are spiral tracheids. It is somewhat difficult to 
identify each of the tissues within this seed. The hard 
integument is the sporangial wall. It is only one cell in 
thickness and the palisade-like cells are columnar in lon- 
gitudinal section with a length two to three times the 
diameter. In transverse section the cells of the integu- 
ment are roughly hexagonal, sometimes quadragonal. 
The cells are usually filled with a dense material, which 
is sometimes limited to the peripheries of the cell cavities. 
The functional or ‘‘seed’’ megaspore of typical species of 
Lepidocarpon is trequently accompanied by three abor- 
tive spores which are appressed to the triradiate crest of 
the functional spore. In only a few of our preparations 
have abortive spores been observed and all of the evidence 
points to the fact that in life the degeneration of the 
abortive spores was usually complete. Schopf (11) and 
Arnold (1) have both observed isolated spores of this 
type. Schopf correctly identified his spores with Lepido- 
carpon and Illiniocarpon. Arnold isolated his specimens 
from a poorly preserved cone from Mazon Creek, Illinois. 
In the case of Arnold’s specimen (Lepidostrobus braid- 
woodensis Arnold), the spores probably were not those of 
a Lepidocarpon. In the seeds from the Iowa coal balls 
[ 97 ] 
