352 
OHIO BIOLOGICAL SURVEY 
EXPLANATION OF PLATE XIII 
Fig. 1. Five paraphyses of Rhizocarpon alboairum to illustrate types of simple and 
branched forms found in the same hymenium. X 450. 
Fig. 2. A section of the thallus of Bac/W/fl rubella and two cells of the woody sub¬ 
stratum: a, the upper densely interwoven portion of the thallus; b, part of 
the less densely interwoven portion below; c, the algal-host cells; d, one of 
the cells of the woody substratum and three hypal rhizoids within it. X 450. 
Fig. 3. Spores of Lecidea enteroleuca to illustrate the simple, hyaline type. X 760. 
Fig. 4. Spores of Biatorina chalybeia to illustrate the 2-celled, hyaline type. X 760. 
Fig. 5. Spores of Bilimbia trachona to illustrate the several-celled, hyaline, fusiform 
or dactyloid type. X 760. 
Fig. 6. Spores of Bacidia fuscorubella to illustrate the several-celled, hyaline, acicular 
type. X 760. 
Fig. 7. Spores of Bacidia umbrina to illustrate the several-celled, hyaline, hamate or 
spirally twisted type. X 760. 
Fig. 8. Spores of Rhizocarpon alboatrum to illustrate the several-celled to many- 
celled and muriform, hyaline to brown type. X 760. 
Fig. 9. Spores of Rhizocarpon petraeum of the same type as those shown in the last 
figure, but larger, and usually composed of more cells. X 760. 
Fig. 10. A vertical section through an apothecium of Lecidea rupestris: a, the hyme¬ 
nium, composed of asci and paraphyses; b, the hypothecium; c, the mycel¬ 
ium, the cells of the algal host, and particles of the limestone on which the 
plant was growing; d, the weak, light-colored, covered exciple. X 79. 
Fig. 11. A vertical section through an apothecium of Buellia parasema, the thallus 
below, and a portion of the woody substratum: a, the hymenium, composed 
of asci and paraphyses; b, the strongly developed, dark colored exciple; c, 
the dark colored hypothecium; d, the thallus, composed of interwoven 
hyphae, and enclosing cells of the algal host, a portion of the woody 
substratum. X 79. 
Fig. 12. One branched and one unbranched paraphysis of Buellia parasema. X 450. 
Fig. 13. An ascus of Buella parasema, containing 8 spores. X 450. 
The figures were outlined with camera lucida and drawn on the table, close to the base of the 
microscope, 100 mm. below the stage. They were reduced one-half in making the plate. Figures 2, 
10, and 11 are partly diagrammatical. 
