486 
5. IDIOTHALAMEiE. Pl. cell aph. 
Fam. V. 5, IDIOTHALAMEIE. Algarum pars, Linn. 
Lichenum pars , Jussieu, Acharius* 
Thallus crustlike or leatlierlike ; sporidia scattered, in- 
nate in the substance, and in a nucleus or proligerous flake 
covered by the thallus, or by a single or double perithe- 
cium .—Thallus perennial, terrestrial, or parasitical; greenish 
or becoming so when wetted ; absorbing water by the sur- 
face, and transmitting it to all parts. 
A. Thallus leatherlike , shrublike ; apothecia tubercular ; 
perithecium 0. Rhizomorphidae. 
Thallus crustlike, cartilaginous, 
branched, shrublike, upright Sph^erophoron. 122* 
Thallus crustlike, membranaceous, 
branched, creeping, prostrate Rhizomorpha. 123. 
B. Thallus crustlike; apothecia warilike ; perithecium 
distinct. Variolaridae. 
Thallus crustlike Variolaria. 124* 
C. Thallus crustlike ; apothecia w artlike ; perithecium 
distinct. Porinidse. 
Nucleus single; 
perithecium simple, black Pyrenula. 125. 
Nucleus simple; perithecium double, 
first thick, second membranaceous. . . Thelotrema. 126. 
Nucleus mostly single, covered ; 
perithecium simple Porina. 127- 
D. Thallus crustlike ; apothecia round , not bordered; 
perithecium distinct. Verrucaridse. 
Thallus cartilaginous, membranaceous, 
perithecium double Lejophlea. 128. 
Thallus crustlike, cracked in beds, 
or powdery; perithecium double Lithocia. 129. 
Thallus soft, towlike, spongy or 
cobwebby; perithecium double Inoderma. 130. 
Thallus leaflike or shieldlike; 
perithecium single Endocarpon. 131. 
