Both kinds of spores were provided with an equatorial 
flange. The foliage was dimorphic. The megaspores re- 
sembled those of the existing Selaginella caulescens. 
They measured 500 to 650 micra in diameter. The mi- 
crospores, in contrast, attained a diameter of only 40 to 
60 micra. 
Halle (8) in 1907, transferred Lycopodites primaevus 
Goldenberg and L. elongatus Goldenberg (9) to Selag- 
inelhites. ‘These two species apparently bore only mega- 
spores in the preserved sporangia. Those of Se/aginellites 
primaevus attained a diameter of 400 to 500 micra, and 
those of Selaginellites elongatus had a diameter of 450 
micra. 
Curiously enough Zeiller compared Selaginellites 
Suessi with a third species of Goldenberg (10) Lycopo- 
dites macrophyllus. Spores have not been observed in this 
form, but the sporangia are preserved. They are not 
grouped into strobili, but are borne in the axils of leaves. 
Seward (11) in 1918 described a lower Cretaceous 
(Wealden) Selaginella under the name Selaginella Daw- 
soni. This species was heterosporous. ‘The microspores, 
which were still in tetrads, were finely tuberculate and 
measured 40 micrain diameter. The megaspore number 
could not be ascertained, but their size and ornamenta- 
tion was observed. Their exines were irregularly reticu- 
late and the spore diameter exceeded 300 micra. 
The strobilus of the specimen from the Carboniferous 
of Illinois is distinct from all of the previously described 
fossil forms ‘in possessing the following features: only 
four megaspores in each sporangium, the unusually large 
diameter of 750 micra—including the equatorial flange 
formed by the expanded arcuate ridges of the spore exine, 
and by having the gametophyte preserved. The spores 
are in general similar to the previously described species 
in having reticulated exines, equatorial flanges and large 
[ 128 | 
