A number of groups, each of which was treated in the original Friesian classification as a single genus, have more recently been recognized as comprising several distinct genera. In the Saccardian system the genera Trametes, Daedalea, Merulius, Porothelium, and Fistulina still retain the generic rank assigned to them by Fries, but the old genus Boletus is subdivided into four genera, Boletus, Strobilomyces, Boletinus, and Gyrodon, while Polyporus, originally a very large genus, is subdivided into the genera Polyporus, Fomes, Polystictus, and Poria. This arrangement was in part suggested by Fries in his later works, and is accepted by M. C. Cooke, as indicated in his latest work on fungi. Quoting M. C. Cooke, "_Strobilomyces_ is _Boletus_ with a rough warty and scaly pileus; _Boletinus_ is _Boletus_ with short, large radiating pores; and _Gyrodon_ is _Boletus_ with elongated sinuate irregular pores, all fleshy, firm fungi of robust habit, possessing stem and cap." The species of the genus Polyporus as now restricted are somewhat fleshy in the young stage, shrinking as they mature and dry, and becoming indurated with age. In Fomes the species, of woody consistency from the first, have no room for shrinkage, and are quite rigid; the tubes being in strata, and the strata growing yearly, the species are virtually perennial. The pileus of the plant shows a rigid polished crust resulting from resinous exudations. In Polystictus the plants are usually small, thin, tough, and irregular in outline, the tubes exceedingly short, with thin walls, which easily split up, giving the pores at times a toothed or fringed appearance. The surface is velvety, or hairy, and zoned in varying colors. They are very common upon decaying tree stumps, often covering the surface of the stump in gaily colored layers. Not esculent. Poria is composed of resupinate species with the pores normally in a single series, the whole stratum spread over, and adhering to the matrix. The species are coriaceous or woody. Not esculent. The plants of the genus Trametes allied to Fomes are epiphytal, with the trama the same in substance and color as the hymenophore. The tubes do not form in regular strata, but are sunk into the substance of the pileus. The plants are coriaceous, and none are edible. Daedalea closely resembles _Trametes_ with the tubes forming deep labyrinthiform depressions. Whole plant woody, sessile. Hexagonia, allied by its characteristics to Polystictus, has large hexagonal pores, with firm, entire dissepiments. In Favolus the plants are slightly fleshy and substipitate with the pores angular, and radiating from the stem. Not edible. The species of the genus Laschia are recognized by the shallow irregular pores and the vein like character of their dissepiments (or pore walls). Substance slightly gelatinous.