=Antagonistic symbiosis=, hurtful parasitism of one lichen on another, 261 _et seq._ =Apothecium=, open or disc-shaped fructification, 11, 156 _et passim_. Veiled apothecium, 169. Closed or open at first, 182. =Archilichens=, lichens in which the gonidia are bright green (Chlorophyceae), 52, 55 _et passim_. =Ardella=, the small spot-like apothecium of Arthoniaceae, 158. =Areola= (areolate), small space marked out by lines or chinks on the surface of the thallus, 73 _et passim_. =Arthrosterigma=, septate tissue-like sterigma (spermatiophore), 197. =Ascogonium=, the cell or cells that produce ascogenous hyphae, 180 _et seq._ =Ascolichens=, lichens in which the fungus is an Ascomycete, 159, 173 _et passim_. =Ascus=, enlarged cell in which a definite number of spores (usually 8) are developed; cf. theca, 157, 184. =Ascyphous=, podetia without scyphi, 119 _et passim_. =Biatorine=, apothecia that are soft or waxy, and often brightly coloured, as in _Biatora_, 158. =Blasteniospore=, see _polarilocular spore_. =Byssoid=, slender, thread-like, as in the old genus _Byssus_. =Campylidium=, supposed new type of fructification in lichens, 191. =Capitulum=, the globose apical apothecium of Coniocarpineae; cf. mazaedium, 319. =Carpogonium=, primordial stage of fructification, 160, 164 _et passim_. =Cephalodium=, irregular outgrowth from the thallus enclosing mostly blue-green algae; or intruded packet of algae within the thallus, 11, 133 _et passim_. =Chrondroid=, hard and tough like cartilage, a term applied to strengthening strands of hyphae, 104, 114. =Chroolepoid=, like the genus _Chroolepis_ (_Trentepohlia_). =Chrysogonidia=, yellow algal cells (_Trentepohlia_). =Cilium=, hair-like outgrowth from surface or margin of thallus, or margin of apothecium, 91. =Consortium= (consortism), mutual association of fungus and alga (Reinke); also termed “mutualism,” 31, 313. =Corticolous=, living on the bark of trees, 363. =Crustaceous=, crust-like closely adhering thallus, 70-79. =Cyphella=, minute cup-like depression on the under surface of the thallus (_Sticta_, etc.), 11, 126. =Decomposed=, term applied to cortex formed of gelatinous indistinct hyphae (amorphous), 73-81 _et passim_, 357. =Determinate=, thallus with a definite outline, 72. =Dimidiate=, term applied to the perithecium, when the outer wall covers only the upper portion, 159. =Discoid=, disc-like, an open rounded apothecium, 156. =Discolichens=, in which the fructification is an apothecium, 160 _et seq._ =Dual hypothesis=, the theory of two organisms present in the lichen thallus, 27 _et seq._ =Effigurate=, having a distinct form or figure; cf. placodioid, 80, 201. =Endobasidial=, Steiner’s term for sporophore with a secondary sporiferous branch, 200. =Endogenous=, produced internally, as spores in an ascus, 179; see also under thallus. =Endolithic=, embedded in the rock, 75.