es_ (Bull.) Rost., p. 181.

Fig. 1. A group of sporangia, x 5.

Fig. 1 _a_. A single spore, x 1600.

Fig. 1 _b_. Tip of the columella with its branches, x 50.

_Comatricha longa_ Peck, p. 175.

Fig. 2. A single empty sporangium, x 6.

Fig. 2 _a_. A part of the same taken near the apex, x 60.

Fig. 2 _b_. A spore, x 1400.

_Comatricha aequalis_ Peck, p. 180.

Fig. 3. A single sporangium, x 10.

Fig. 3 _a_. The columella and capillitium, x 60.

Fig. 3 _b_. A single spore, x 1600.

Figs. 3 _c_ and 3 _d_. Sporangia to which the peridium still adheres,
although in 3 _c_ in shreds.

_Stemonitis fusca_ Rost., p. 160.

Fig. 4. A group of sporangia, x 3.

Fig. 4 _a_. A part of the columella and capillitium, x 60.

Fig. 4 _b_. A single spore, x 1400.

_Stemonitis axifera_ (Bull.) Macbr., p. 168.

Fig. 5. A group of sporangia, x 3.

Fig. 5 _a_. A single spore, x 1400.

Fig. 5 _b_. A part of the capillitium with columella, x 60.

_Stemonitis splendens_, p. 164.

Fig. 6. A group of sporangia, x 3.

Figs. 6 _a_ and 6 _c_. Single spores, the latter x 1400.

Fig. 6 _b_. A part of the columella and branches, x 60.

Fig. 7. A shorter variety of the same species with coarser meshes in
capillitium, x 3.

Fig. 7 _a_. A part of the columella and net, x 60.

[Illustration: PLATE VI]

EXPLANATION OF PLATE VII

_Diachaea splendens_ Peck, p. 187.

Fig. 1. Sporangia and hypothallus, x 25.

Fig. 1 _a_. Capillitium, x 50.

Fig. 1 _b_. Spores, x 900.

Fig. 1 _c_. Portion of the capillitium, x 150.

_Didymium nigripes_ Fr., p. 123.

Fig. 2. Sporangia, x 30.

Fig. 2 _a_. A spore, x 1400.

Fig. 2 _b_. Calcareous crystals from the peridial wall, x 750.

_Didymium melanospermum_ (Pers.) Macbr., p. 121.

Fig. 3. Sporangia, x 10.

Fig. 3 _a_. A single spore, x about 1000.

_Diderma testaceum_ (Schrad.) Pers., p. 137.

Fig. 4. Sporangia; the first exhibiting the two peridial walls and the
spore-mass, x 10.

Fig. 4 _a_. Spore, x 750.

Fig. 4 _b_. Capillitial threads, x 750.

_Diderma globosum_ Pers., p. 134.

Fig. 5. Sporangia; the first with the outer peridium broken away, x 10.

Fig. 5 _a_. A single spore, x 750.

_Mucilago spongiosa_ (Leyss.) Morg., p. 114.

Fig. 6. An aethalium, borne on a grass-stem, natural size.

Fig. 6 _a_. A spore, x 750.

Fig. 6 _b_. Capillitium, with surface calcareous crystals, x 750.

_Diderma crustaceum_ Peck, p. 135.

Fig. 7. A ma