Cordaicarpus, are very numerous, more than one hundred 
individual examples have been found. Of this number 
eight have well preserved dicotyledonous embryos. These 
are the first known Paleozoic embryos. There are nearly 
three hundred microsporangiate strobili and, curiously, 
only six megasporangiate strobili. The polliniferous in¬ 
florescences contain winged pollen-grains each with a 
multicellular gametophyte of approximately twenty to 
thirty cells. In addition there are specimens of vegetative 
buds and enrolled leaves. If these detached parts can sub¬ 
sequently be demonstrated to belong to a single species, 
it will be one of the most completely known Carbonifer¬ 
ous plants. 
Pteridospermae 
The most abundant seed-fern stem type occurring in 
the Iowa coal balls is a tristelic species of Medullosa 
which is most probably identical with Medullosa Noei 
Steidtmann, which in turn belongs to the Medullosa ang- 
lica group. Large petioles, as well as many smaller ones, 
have been prepared for detailed study. Leaves of Neu- 
ropteris Scheuchzeri Hoffman, Neuropteris rarinervis 
Bunbury, and Linopteris cf. obliqua are abundantly pre¬ 
served both as impressions and petrifactions. There are 
several little known fructifications (one a Telangium) 
which occur in the flora. Eight nominal species of de¬ 
tached seeds of the Lagenostoma, Rhabdocarpus , and 
Trigonocarpus types occur sparingly, as well as a variety 
of other undescribed forms. Seeds of the Lagenostoma 
type are rare. 
Filicales 
By delicate manipulation with needles and chisels we 
have been able to expose impressions of two species of 
Pecopteris foliage bearing sori; one an Asterotheca and 
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