_Auricularia sambucina_ (_Auricula judæ_), Judas’-ear, has large fruit-bodies, which may attain the size of several inches, resembling an ear or a mussel shell. In the moist condition they are flesh-coloured, tough and gelatinous, but when dried, become hard, grey and wrinkled; the exterior is covered with short hairs; while the internal surface bears the hymenium. Habitat: stems and branches of old Elder-trees (_Sambucus_). Order 3. =Tremellaceæ.= The _round, pear-shaped, longitudinally divided basidia_ bear 4 _elongated sterigmata_, situated apically, and 4 basidiospores (Fig. 160 _C_, _D_), and are united into the _hymenium_ on the surface of the fruit-body. The fruit-bodies are frequently gelatinous and quivering; similar fruit-bodies are also found in the Dacryomycetaceæ and Hydnaceæ. Simple conidiophores, which appear not infrequently in the basidiocarps, before the basidia, are known in many species. Saprophytes. [Illustration: FIG. 159.--_Peridermium strobi_: æcidia of _Cronartium ribicola_ (nat. size).] [Illustration: FIG. 160.--_B Auricularia sambucina_: _a-d_ basidia in various stages of development; _e_ a sterigma bearing a spore.--_C Tremella lutescens_: _a-d_ basidia seen from various sides (_b_ from above) and in various stages of development; _e_ sterigma with basidiospore (× 400). _D Exidia glandulosa_: _a-c_ various stages in the development of a basidium; _d_ sterigma with basidiospore (× 350).] _Exidia_ has kidney-shaped, oblong basidiospores, and small, hook-like conidia; _E. glandulosa_, _E. albida_, etc., on wood.--_Craterocolla_ has conidiocarps; _C. cerasi_ on Cherry-wood.--_Sebacina incrustans_; the yellow, fleshy, or cartilaginous fruit-bodies are found in autumn covering the ground in moist woods.--_Tremella_ has round basidiospores; _T. mesenterica_ has irregularly-folded, quivering, orange fruit-bodies, about one inch in breadth; _T. lutescens_ (Fig. 161) has orange-yellow conidial-and yellow basidial-layers; _T. frondosa_ has fruit-bodies upwards of a foot in breadth. Order 4. =Pilacraceæ.= The _transversely divided basidia_ have _no sterigmata_, but sessile basidiospores, and fill up the cavity of a _closed_ (_angiocarpic_) _fruit-body_ as a gleba without a regular arrangement (hymenium wanting). _Pilacre fagi_ on the old stems of the Copper-Beech; _P. petersii_, on dried branches of the Hornbeam, has stalked, capitate fruit-bodies. [Illustration: FIG. 161.--_Tremella lutescens_: I and II fruit-bodies (nat. size); III vertical section through a fruit-body; _b_ basidia; _c_ conidia; IV-VI basidia; VII basidiospore with a second spore; VIII a basidiospore with yeast-like budding (cultivated); IX a conidiophore. (III-IX about 400.)] Series 2. =Autobasidiomycetes.=