10 ILLINOIS BIOLOGICAL MONOGRAPHS [478 



opportunity thus afforded of making close comparisons between these 

 forms, I feel that I have at least approximated the truth. 



Especially worthy of note is the occurrence in Porto Rico of sev- 

 eral tropical species on closely related hosts, originally described from 

 the other side of the world, notably M. merrUUi, on Sicyos from the 

 Philippines, M. clavnlata on Ipomoea and M. cyperi on Sedges from 

 Africa. 



It should be remembered that Meliola is preeminently a tropical 

 genus, almost exclusively so, the occurrence therefore of these species 

 in Porto Rico, Africa and the Philippines with no present tropical land 

 connection between these countries implies, either that the Meliolas have 

 in the past been of different climatic range or that they are the residual 

 flora of previously connected tropical lands. 



I wish to acknowledge the very great assistance that I have received 

 from Doctor N. L. Britton and Mr. Percy Wilson in the determination 

 of Phanerogamic hosts, from Miss Slosson, the Pteridophytes, and from 

 Mrs. Agnes Chase the Grasses. 



Meliola, Key to Sections 

 Spores 3-septate, mycelial setae none section A, p. 10 



Spores 4-septate 

 Mycelial setae none 



Perithecium with no setae or appendages 

 Perithecium with setae or with appendages 

 Mycelial setae present 



Perithecium with setae or appendages 

 Perithecium with no setae or appendages 

 Mycelial setae simple, straight 

 Mycelial setae simple, uncinate 

 Mycelial setae usually simple, some- 

 times forked 

 Mycelial setae forked 



Section A 



Spores 3-septate, mycelial setae none 



The members of this section are clearly marked by the 3-septate 

 spores, a character that seems to be invariable, and the three species 

 found in Porto Rico are clearly limited as is shown in the following key. 



Key to Species of Section A 



Perithecium with larvaeform appendages M. puiggarii No. 1 



Perithecium with no larvaeform appendages 



Perithecial setae absent M. manca No. 2 



Perithecial setae present, M. guignardi No. 3 



