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THE GENUS THAYERIA. 43 
given it up, fertile fronds were detected in a single tree at a 
greater altitude. Fifteen fertile fronds were obtained by felling 
the tree. 
With the ample material now in hand from Mindanao and 
Luzon, I conclude that the differences formerly found between 
them are not constant, but that all are one species. This differs 
from Thayerta nectarifera in not being dimorphous. As the ac- 
companying plate shows, the sori are born, as in Aglaomorpha, 
on the constricted upper part of otherwise normal fronds; while 
the sterile lower part of the fertile frond of Thayeria nectarifera 
is pinnate, this frond being stipitate and not humus-collecting. 
The fertile pinnae of Thayeria nectarifera are also more con- 
stricted. The figure in "Malesia" shows no lamina between the 
sori, as is typical of Aglaomorpha § Psygmium; while Thayeria 
Cornucopia has more or less lamina everywhere, as the plate 
shows, but the amount of development of this wing is variable. 
The known species of Thayeria, then, are two: 
T. Cornucopia Copel., of Mindanao and Luzon. 
T« nectarifera (Baker) Cope!., of New Guinea. 
