menium almost
always lighter and commonly hyaline (Figs. 10 and 11, a); paraphyses
usually simple, but branched forms to be found frequently (Figs. 1 and
12), pale throughout or darkened toward the sometimes enlarged apex,
commonly more or less coherent and indistinct at maturity; spores simple
and hyaline to muriform and brown (Figs. 2, 3, 4, 5, 6, 7, 8, 9, and
13).

KEY TO THE GENERA

Spores minute, numerous in each ascus _Biatorella_, p.
Spores larger, usually 8 in each ascus,
Spores hyaline.
Spores one-celled (simple) _Lecidea_, p.
Spores more than one-celled (compound).
Spores 2-celled _Biatorina_, p.
Spores 4- to several-celled.
Spores ellipsoid, fusiform, or dactyloid _Bilimbia_, p.
Spores acicular _Bacidia_, p.
Spores brown, or becoming brown.
Spores 2-celled _Buellia_, p.
Spores 4-celled and becoming muriform _Rhizocarpon_, p.

Biatorella De Not. Giorn. Bot. Ital. 21. 192. 1846.

Thallus granulose to verrucose and subareolate, sometimes inconspicuous
and evanescent; apothecia minute to middle-sized, adnate or more or less
immersed, exciple usually prominent and persistent, but sometimes
becoming covered, disk flat to convex; hypothecium and hymenium pale to
brown; spores simple, hyaline, minute, numerous in each ascus.

KEY TO THE SPECIES OF BIATORELLA

The whole apothecium dark colored 1. B. _simplex_
The disk of the apothecium white-pruinose 2. B. _pruinosa_

1. Biatorella simplex (Dav.) Br. & Rostr. Bot. Tidssk. 3: 241 1869.

_Lichen simplex_ Dav. Trans. Linn. Soc. Lond. 2: 283 pl. 28. f. 2. 1794.

Thallus thin and smooth or thicker and roughened, sometimes subareolate,
ash-white to green-gray and darkening, rarely disappearing; apothecia
minute to middle-sized, 0.2 to 0.8 mm. in diameter, adnate, scattered
or crowded, rounded or variously irregular, black but usually dark red
when damp, flat or slightly convex, the thin exciple raised and
persistent; hypothecium light or darker brown; hymenium pale or tinged
brown; paraphyses semi-distinct to coherent-indistinct; asci
cylindrico-clavate; spores oblong-ellipsoid, 3 to 5 mic. long and 1 to
1.5 mic. wide.

Collected in Butler, Adams, Montgomery, Hocking, and Ross counties. On
limestone. Not previously reported from Ohio, but probably freque