LITERATURE CrPED 
Andrews, H. N. 1965. Contributions to our knowledge of American 
Carboniferous floras, VII. Some pteridosperm stems from lowa, 
Ann. Mo. Bot. Gard. 32: 323-360. 
and J. A. Kernen. 1946. Contributions, ete. VIII. Another 
Medullosa from lowa, Ann, Mo. Bot, Gard, 835: 141-146, 
Baxter, R. W. 1949. Some pteridosperm stems and _ fructifications 
with particular reference to the Medullosae. Ann, Mo. Bot. Gard. 
: ~ 7 
36: 287-352. 
Darrah, W. C. 191. Studies of American coal balls. Am. Journ. 
Science 289: 385-53. 
DeFraine, EK. 1912, On the structure and affinities of Sufeliffia, in the 
light of a newly discovered specimen, Ann. Bot. 26: 1081-1066, 
1914. On Medullosa centrofilis, a species of Medullosa trom the 
Lower Coal Measures. Ann. Bot. 28: 251-264, 
Schopt, J. M. 1989. Medullosa distelica, x» new species of the anglica 
vroup of Medullosa, Atm. Journ, Bot. 26: 196-207, 
Scott, D. H. 1899. On the structure and afhnities of fossil plants 
from the Paleozoic rocks. IIT. On Medullosa anglica, a new repre- 
sentative of the Cycadotilices. Phil. Trans. Roy. Soc. Series B 191: 
$1-126, 
19tt. On Medullosa pusilla, Roy. Soc, Lond, Proc. Ser, B87: 
C2228. 
Steidtmann, W. EB, 1944. ‘The anatomy and afhnities of Medul/osa 
Noei Steidtmann, and associated foliage, roots, and seeds. Univ. 
Mich., Contrib. Mus. Paleont. G: 131-166, 
Stewart, WON. 1951. Medullosa pandurata sp, nov. from the McLeans- 
boro Group of Illinois. Am. Journ, Bot. 38: 709-718. 
Weber, O., and J. ‘Il’. Sterzel. 1896. Beitrige zur Kenntnis der 
Medullosae. Ber. Naturwiss. Gesell. 18: 44-1438. 
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