The Collemaceae of Ohio 37 
factory than Schulze’s solution. The measurements of microscopic 
features were taken from specimens treated with water only. 
Limiting the area studied to a region near at hand gave the ad¬ 
vantage of being able to secure material in fresh condition easily. While 
our area conforms to the requirements of the Ohio Biological Survey, 
the collecting has been conhned to the southwestern portion of the state, 
extending roughly about one-fourth of the distance from the southern 
boundary to the northern and somewhat more than one-third of the way 
from the western boundary to the eastern. The principal collecting 
grounds are about Oxford, Eaton, West Alexandria, Mason, Washington 
Court House, Greenheld, Paint, Bainbridge, Peebles, and Cincinnati. 
Collections made by others in various portions of the state have been 
studied through material loaned from the herbarium of the Ohio State 
University and have given a fairly satisfactory knowledge of the dis¬ 
tribution of several of the species within the state as a whole. 
Just what changes in limitations of species would result from the 
employment of a new taxonomic method could not be known until we 
had examined a considerable number of species of the family. While 
our paper covers only the sixteen species of the Collcinaccac known in 
Ohio, we have made preliminary examinations of about as many more. 
This means that we have covered approximately one-fourth of the 
species known to occur in North America. Thus far our method has not 
required any changes in species-limits. Each species studied has shown 
a sufficient number of morphological characters to mark it as distinct, 
or has been found to modify the size, form, color, or general appearance 
of the algal host in a peculiar manner. In our descriptions, the power 
of modifying the algal-host colony has been treated as a specific, 
physiological character of each species of lichen. Since the algal host 
rather than any portion of the lichen itself, except the apothecia, is con¬ 
spicuously visible in the field, we have given first under each name of a 
species a statement concerning the manner in which the lichen has 
modified its host. This brings into prominence that which is seen plainly 
on first observation, and at the same time avoids the error of describing 
the algal host as a portion of the lichen. Eollowing the statement re¬ 
garding the transforming action of the lichen on the algal host, such 
characters of the lichen itself as have seemed to have considerable 
diagnostic value have been recorded. 
We have tried to present a method workable for the species found 
in the area treated in this paper and also like that which must be em¬ 
ployed when our method is extended to include the Collcinaccac of a 
