Fam. I. HYMENOMYCETES.

Thalamium expanded into a membrane (called hymenium), centrifugal, occupying the lower surface in Pileates, or the exterior if not discrete from the pileus, indefinite. The hymenium is made of short and thin asci, normally not free, but crowded together. Sporidia are exerted at the tips of the asci, often quaternate, then separating like powder and not elastically exploded. Centrifugal vegetation! discrete; floccose structure, composite; with a never-spurious (i.e., formed by the matrix) mycelium, subperennial! developing a most often ephemeral fructification at a definite time and when the weather permits (hence they abound in one year, and grow scarce in another). It is manifest that the asci of genuine Hymenomycetes, as first observed in letters by the celebrated BERKELEY, are exosporous and not endosporous; for once, we dare to depart from the opinion of all predecessors. Only in the rays leading to Discomycetes—to these, if one wishes, they are easily transferred (Gen. 46!, 47 unless this is an optical error?, 54, 55, 62-64)—are they endosporous; but on account of habit, morphosis, and customary use, they are cited here at the same time.

Ord. I. AGARICINI. Hymenium inferior, originally effigured, lamellate. The lamellae radiating from the stipe or center, simple or branched (only rarely anastomosing at the base), made of a double lamina, bearing asci outwardly on both sides. — Nature has not found any type, not even among the Compositae, in the entire vegetable world in so many most diverse forms. Genera are not to be separated from the veil, etc., but only from the lamellae and especially their trama the central layer of the gill (i.e., the partition between the two membranes of the lamellae) — many were formerly to be separated from the primary genus.

I. AGARICUS. Lamellae membranaceous, persistent, acute at the edge, trama subfloccose and non-concreting with the hymenophorum the part of the fungus supporting the hymenium. Asci perfect, crowded, shedding dry sporidia. Fleshy fungi, putrescent and not reviving when dried! — For an analysis of the arrangement of this most vast genus, see at the end of the family.