In systematic works upon the Lichens, the saucers and their contents are included in the term apothecia, the saucer alone being called the _excip´ulum_ (_excipulum_, a receiver); the mass of asci and paraphyses forming the _nucleus_ or _thalámium_ (θἁλαμος, a bed). The yellow spores are very minute, each ascus containing eight of them, and they are divided by a transverse partition or septum. Near the margins of the lobes of the thallus are small dark points. These are the pouting mouths of little capsules (_spermogonia_) sunk in the substance of the thallus, and containing numerous filaments, terminated by very minute stick-shaped bodies (_spermatia_), which break off and escape through the orifices of the capsules. These are probably the representatives of the anthers of flowering plants and of the antheridia of the ferns. They are, however, so difficult to find and examine, that I must refer to the Dictionary for a further description and figures of them. LECIDIN´EÆ.--This family contains the genus _Cladónia_, three or four species of which are common on boggy heaths, banks, &c., viz. _Cladonia coccif´era_, the Scarlet Cup-moss (Pl. II. fig. 21); _C. pyxidáta_, the Common Cup-moss (Pl. II. fig. 23); _C. vermiculáris_ (Pl. II. fig. 22); and _C. rangiferína_, the Reindeer Moss (Pl. II. fig. 24). The thallus of these Lichens forms little rounded irregularly overlapping scales, with scalloped edges, overgrowing the surface upon which the Lichens are found. The fruit-stalks, or _podétia_ (ποῦς, a foot), are hollow (fistulose), and either simple and dilated into cups (Pl. II. fig. 23), or branched with the corners or angles between the adjacent branches perforated. The apothecia in the young state resemble those of _Parmelia_ on a small scale; but as they approach maturity, the centre becomes pushed up, so that the spore-layer is extended over the ends of the stalks. In _C. coccifera_ and _pyxidata_ the cups are proliferous at the margin; _i. e._, branches upon which the apothecia are placed arise from it. The asci and paraphyses are very minute, but do not differ essentially in structure from those of _Parmelia_. In _C. vermicularis_ the podetia are pointed and more solid than in the other species, the apothecia forming very minute spots at their apices. GRAPHID´EÆ.--To this family belong _Gráphis scripta_ (Pl. II. fig. 26) and _Opeg´rapha betulína_ (Pl. II. fig. 30). These little Lichens are easily overlooked, from the thin and but slightly raised thallus being only visible to the naked eye as a discoloration of the bark of the trees upon which they grow; while the fructification is very minute, forming little black streaks or _lirel´læ_ (_lira_, a furrow), irregularly arranged, and resembling somewhat the letters of some of the Oriental alphabets.