inns rcemnnons 
BOTANICAL MUSEUM LEAFLETS 
HARVARD UNIVERSITY 
CamBripGr, Massacnusetts, AprIL 30, 1937 
CODONOTHECA AND CROSSOTHECA: 
POLLENIFEROUS STRUCTURES 
OF PTERIDOSPERMS 
BY 
WiniiamM C. Darran 
THE PTERIDOSPERMS or seed-ferns are of especial evo- 
lutionary significance because in a number of structures 
they foreshadow the cycads and higher seed-plants. The 
main interest in the pteridosperms centers in their mode 
of fructification which is generally considered to be non- 
strobiloid, having true seeds and typical archi-gymno- 
spermous pollen in sacs borne on pinnatified branches of 
fern-like habit. 
One of the important and meagerly known microspo- 
rangiate form-genera is Codonotheca which belongs to 
the medullosan seed-ferns. 
Halle (7 )' has published the only comprehensive sur- 
vey of pteridosperm fructifications and has given direc- 
tion to the interpretations concerning the polleniferous 
structures. 
It was Sellards’ (74) opinion that Codonotheca was the 
polleniferous structure of Neuropteris decipiens Lesque- 
reux (17). I am inclined to this opinion because of the 
similarity of cuticlar and stomatal structures of Codono- 
theca to those of Neuropteris decipiens. There is also some 
resemblance of its cuticle to that of Newropteris rariner- 
‘Italic numbers in parentheses refer to Bibliography. 
[ 158 ] 
