characters, the aberrancy being with respect to the spores, on which
account the two genera are placed in another family, the _Buelliaceae_,
by some workers, perhaps with sufficient reason.

The algal host is _Pleurococcus_-like (Fig. 2, c) in nearly all species
of the _Lecideaceae_; but the host cells are so hypertrophied and
distorted that their generic rank is often difficult to ascertain,
except by cultivation outside of the lichen thallus. The algal-host
cells are few in number in some of the species and are sometimes absent
during a portion of the life history of the lichen. The host is usually
found throughout the superficial portions of the thallus, except near
the upper surface, from which portion the algae are usually absent,
except in a dead or dying condition, difficult to detect.

The writer has collected the _Lecideaceae_, with other fungi, in Butler
County for fifteen years, and has worked for the Ohio Biological Survey
in Preble, Warren, Highland, Fairfield, Adams, Hocking, and Lake
counties. Besides these collections made by the writer, a few specimens
were examined from Champaign, Hamilton, Wayne, Morgan, Madison,
Muskingum, Franklin, Vinton, and Summit counties. Of the 37 species
treated in this paper, 24 had not been reported from Ohio previously.

[Footnote A: Contributions from the Botanical Laboratory of Miami
University.--XVIII]




_Systematic Account._