GLOSSARY 



Acicular. Slender or needle-shaped, as the spores in species of Bacidia. 



Adnate. As applied to the ascocarp, attached to the thallus or substratum by the 

 whole lower side. 



Algoid. Alga-like, applied to the exciple in species of the Collemaceae, consisting 

 of hyphae and algae. 



Amphithecium. A layer of tissue continuing upward from the hypothecium in 

 some angiocarpic lichens and nearly surrounding the hymenium. 



Angiocarpic. Having the hymenium inclosed by a perithecial wall, by an amphi- 

 thecium, or by both structures. 



Apothecium. An open or disk-shaped ascocarp. 



Areole. A small area of a lichen thallus, separated from other similar areas by 

 minute chinks. 



Ascocarp. The spore-bearing organ, consisting of the hymenium, the epithecium, 



the hypothecium. and the exciple or exciples. 

 Ascogenous. Ascus-producing. 



Ascus. A specialized hyphal cell in which the spores are produced. 

 Biatoroid. Resembling the species of Lecidea in the section Biatora ; used specially 



of apothecial structure. 



Cephalodium. A small, regular or irregular outgrowth appearing on the surface 

 of a few lichen thalli, containing algal cells and hyphae, usually inclosed 

 finally in plectenchymatous cortex. 



Cilium. A slender filament, composed of a bundle of hyphae, occurring on the 

 upper surface or at the margin of the thallus. 



Coralloid. Coral-like; as applied to the outgrowths on the thalli in foliose and 



fruticose forms. 

 Cortex. Plectenchyma forming the upper and lower protective layers in many 



lichen thalli. 

 Crustose. As applied to some lichen thalli, crustlike, or closely attached to the 



substratum and usually without distinct cortex. 

 Cyphella. A minute depression in the undersurface of certain lichen thalli. 

 Dermis. A distinctly marked layer above the upper cortex, consisting of flattened 



cells. 

 Difform. Irregular in form, as in certain apothecia. 

 Dimidiate. Applied to the perithecial wall when the outer wall covers only the 



upper portion. 

 Ectotrophic. Lying on the surface of the thallus. 

 Ellipsoid. In the form of an ellipse, or oblong with round ends. 

 Endotrophic. Within the thallus. 

 Epilithic. Upon rocks. 

 Epiphloedal. Upon bark. 



Epithecium. A structureless thalloid remnant lying upon the hymenium. 

 Exciple. A layer surrounding the hymenium laterally and sometimes developed 



into a perithecial wall. 



Exosporium. The outer coat of the spore wall. 



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