the degree of variation in each form is unknown, and it 
is convenient to have a purely artificial method of class- 
ification. In this manner one may identify with reason- 
able accuracy a great number of objects without entering 
into the difficult morphological problem of determining 
botanical relationships. No attempt is made here to re- 
duce the name Cystosporites to a synonymous position. 
In 1879, Lesquereux (8) described, under the name of 
Lepidocystis, sporangia which were either isolated or at- 
tached to axes of unknown character. He himself said, 
‘*The limitations of this genus are vague and uncertain. ”’ 
However, he astutely referred the majority of these pe- 
culiar fructifications to the lycopods. The capsules are 
cylindrical or ellipsoidal and are smooth or angular. I 
have studied the type series of Lesquereux’s species and 
have recognized two major groups. Sometimes, as in Lep- 
idocystis fraxiniformis Lesquereux, many spores are to 
be found within the sporangium. In other cases, with a 
single spore, the bladder-like sporangia, which were orig- 
inally inflated, have been flattened during preservation. 
In Lepidocystis vesicularis Lesquereux, an example of 
the latter group, the large sporangia are oval or nearly 
square in outline. The average diameter of this type is 
1 cm. The occurrence of impressions of such large spo- 
rangial organs in rocks of Upper Carboniferous age, and 
of a few forms probably related to them in rocks of the 
Lower Carboniferous age, suggests that some charac- 
teristic feature, probably the presence of protective tis- 
sues in the sporangial wall, made preservation possible. 
It should be observed that the sporangial wall of Lep- 
wdocarpon has such construction. 
The recent discovery of a new Lepidocarpon has shown 
an unexpected relationship between Lepidocystis and 
Lepidocarpon. Moreover, it is the first case of a Lepido- 
carpon in which the sporangium is shed free from the 
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