Ohio Biological Survey, Bull. 10, Vol. 11, No. 6 | Page 2

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.
LECIDEACEAE
Thallus crustose, without plectenchymatous cortex (Fig. 2, a), varying from granulose and often evanescent to conspicuous, areolate, or even subsquamulose conditions, attached to the substratum by hyphal rhizoids (Fig. 2, d), and in a few instances extending up as a veil and surrounding the apothecia laterally, the hyphae densely interwoven toward the upper surface, but more loosely disposed below (Fig. 2, a and b); apothecia usually minute or small, commonly rounded, the exciple weak and obscure (Fig. 10, d), or more strongly developed when conspicuous and much darker in color (Fig. 11, b); hypothecium varying from hyaline to dark brown (Fig. 10, b and Fig. 11, c); hymenium 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 frequent where there is limestone, though inconspicuous and easily overlooked.
2. Biatorella pruinosa (J.E. Smith) Mudd Man. Brit. Lich. 191. 1861.
Lichen pruinosus J.E. Smith in Sowerby, Eng. Bot. 32: pl. 2244 1811.
Thallus light colored, usually thin and smooth, rarely disappearing; apothecia minute to middle-sized, 0.2 to 1 mm. in diameter, adnate scattered or crowded, flat or slightly convex, the disk pruinose, and the exciple persistent; hypothecium lighter or darker brown; hymenium usually pale; paraphyses coherent and becoming indistinct; asci cylindrico-clavate; spores oblong-ellipsoid, 3 to 5 mic. long and 1 to 1.5 mic. wide.
Collected in Butler and Adams counties. On limestone. Not previously reported from Ohio, but often occurring with the last in limestone areas.

Lecidea Ach. Meth. Lich. XXX. 32. pl. 2. f. 1, 2. 1803.
Thallus smooth, roughened, or verrucose, in some species chinky to areolate, or even subsquamulose, rarely rudimentary and evanescent; apothecia minute to middle-sized, usually adnate, but rarely sessile or immersed, with pale to black, and flat to strongly convex disk; exciple and hypothecium from pale to dark brown in section; hymenium lighter,