Oligocarpia antedates the Triassic and thus is older 
than any of the typical members of the family. It has 
been observed that the fructification of Oligocarpia, 
though distinct, bears close resemblance to those fructi- 
fications characteristic of the Gleicheniaceae. 
Six species of Oligocarpia have been reported from 
Carboniferous rocks of North America: O. gutbiert Goep- 
pert, O. alabamensis Lesquereux, O.flagellaris Lesque- 
reux, O. missouriensis D. White, O.kansasensis Sellards, 
and O.brongniarti Stur. 
Ina collection of fossil plants from the Mazon Creek 
beds recently sent to the Botanical Museum of Harvard 
University by Mr. F.O.’Thompson of Des Moines, Lowa, 
there are excellent fruiting examples of a typical Oligo- 
carpia Which cannot be referred to any of the described 
species. [It is noteworthy that Lesquereux labelled sim- 
ilar sterile specimens and one poorly preserved fertile 
specimen as ‘‘Pecopteris sp. nov.”’ | propose to name this 
species Oligocarpia vera. 
This new species is especially interesting because each 
sporangium possesses a uniseriate annulus. Serial trans- 
verse sections were made through 20 sori by the nitro- 
cellulose peel method. It was possible to take from 8 to 
14 peels per sorus. The etching solution necessary to dis- 
solve the mineral matrix away from the ‘‘carbonized”’ 
sorus was 5% hydrochloric acid. 
OLiGocaRPIA Goeppert 1841 Gattungen der Fossile 
Pflanzen Lief. i, 1; p. 3. 
Genotype: Oligocarpia guthiert Goeppert pl. & f. 1,2. 
Original generic description: ‘‘Frons bipinnata, pin- 
nulis aequalibus. Nervi primari flexuosi apicem versus in 
dichotomias soluti, nervi secondarii simplices dichoto- 
mive, inferiores simplices ante marginem evanescentes 
apice sorigeri, superiores dichotomi excurrentes. Sori e 
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