360 
OHIO BIOLOGICAL SURVEY 
Fig. 1 
Fig. 2 
Fig. 3 
Fig. 4 
EXPLANATION OF PLATE XIV 
A section through the thallus of Peltigera canina, showing the cortex above 
and the medulla below, the medullary hyphae of the lower portion running 
in a somewhat horizontal direction. The algal cells shaded. X 380. 
A section through the thallus of Nephroma helvetica, showing the cortices, upper 
and lower, and the mycelial medulla within. The algal cell shaded. X 760 
A section through a cephalodium of Peltigera aphthosa; a, the surrounding 
cortex; b, the internal hyphae and the cells of the algal host; c, the support¬ 
ing hyphae from the thallus below. Partly diagramatic. X 48. 
A small portion of a section through the exciple of Peltigera canina, showing 
the plectenchymatous structure. X 380. 
