Marattiales. Latterly, many students regard it as probably a 
seed-bearing fern (Pteridosperm). 
Stauropteris is a true fern, as is shown by the cross-shaped form 
of the conducting tissue in the stem, and the ring-bearing (annu- 
late) sporangia attached to the tips of the branches. It 1s found 
in the Carboniferous of Europe, and is not very completely known. 
The main axis of the frond is forked, and repeated branching gives 
it a bush-like appearance quite different from that of ordinary 
fern fronds. 
A great many species of Pecopteris, based upon impressions of 
the fronds, have been described from the Carboniferous and Per- 
mian rocks, and are evidently not all related to one another. The 
typical Pecopteris fronds are large and usually tri- or quadri- 
pinnate, with the spores in groups (syangia) on the under side 
of the entire rounded pinnules. Some of these stems, when petri- 
fied, have been referred to a genus called Psaronius (starling 
stones), a name derived from the speckled appearance of their 
+ 
polished surfaces. 
They are abundant in Saxony and polished specimens were espe- 
cially prized as decorative objects in the eighteenth century. A 
great variety of species from the Carboniferous and Permian have 
been investigated, and sometimes these tree-fern trunks are also 
preserved as impressions (Caulopteris, Megaphyton). Some have 
the fronds arranged in crowded spirals and others in two or four 
vertical rows. The trunk is usually surrounded by a broad zone 
of closely packed adventitious roots. The fronds, spore containing 
organs (synangia), and stem anatomy are more like the existing 
ferns belonging to the small tropical fern family, Marattiaceae, 
than they are like any other modern ferns. 
The single certain seed-fern shown, Hospermatopteris, is at the 
right in the transparency, and superficially is indistinguishable from 
the modern tree-ferns growing in the Garden greenhouses. It is 
also one of the oldest known seed-ferns. Other and later seed- 
ferns from the Carboniferous and Permian are much more com- 
pletely known, but Lospermatopicris is of special interest since so 
many of their stumps have been found standing in the rocks alonz 
Schoharie Creek, near Gilboa, N. Y., just as they grew in upper 
Devonian time. They are found at several different levels, and 
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