.

_Cribraria aurantiaca_ Schrad., p. 221.

Fig. 3. Sporangium containing spores, x 30.

_Cribraria microcarpa_ Schrad., p. 226.

Fig. 4. Sporangium containing spores, x 30.

_Cribraria tenella_ Schrad., p. 225.

Fig. 5. Sporangium containing spores, x 40.

_Cribraria minutissima_ Schw., p. 220.

Fig. 6. A single sporangium calyculate, x 50.

Fig. 6 _a_. A smaller sporangium without calyx, with spore-mass.

_Cribraria cuprea_ Morg., p. 229.

Fig. 7. A single sporangium, x 50.

_Cribraria violacea_ Rex, p. 227.

Fig. 8. A single sporangium, x 40.

_Cribraria piriformis_ Schrad., p. 224.

Fig. 9. A single sporangium, x 30.

_Perichaena depressa_ (Libert) Rost., p. 242.

Fig. 10. A cluster of sporangia, one open, x 8.

_Physarum nicaraguense_ Macbr., p. 83.

Fig. 11. Single sporangium, x 10.

Fig. 11 _a_. A cluster of sporangia and hypothallus, x 5.

[Illustration: PLATE XVII]

EXPLANATION OF PLATE XVIII

_Margarita metallica_ (Berk. & Br.) List., p. 237.

Fig. 1. A group of sporangia, x 15.

Fig. 1 _a_. Capillitium and spores, x 300.

Fig. 1 _b_. A single spore, x 1200.

_Diderma cor-rubrum_ n. s., p. 140.

Fig. 2. A group of sporangia, x 15.

_Diderma asteroides_ List., p. 143.

Fig. 3. Sporangia-spread, x 6.

Fig. 3 _a_. Same sporangia still unopened, x 4.

_Comatricha laxa_ Rost., Cf. Pl. V., 5 & 5 _a_, p. 184.

Fig. 4. Sporangia, x 10.

_Diderma lyallii_ (Mass.) Macbr., p. 136.

Fig. 5. A group of sporangia, x 10.

Fig. 5 _a_. Capillitium and spores, x 200.

_Lepidoderma chailletii_ Rost., p. 146.

Fig. 6. A group of sporangia, x 15.

Fig. 6 _a_. Capillitium and spores, x 150.

Fig. 6 _b_. A single spore, x 800.

_Didymium anellus_ Morg., p. 117.

Fig. 7. A group of sporangia, x 10.

_Diderma radiatum_ Linn., p. 141.

Fig. 8. A group of sporangia, x 8.

_Physarum diderma_ Rost., p. 55.

Fig. 9. A group of sporangia, x 10.

_Diderma rugosum_ (Rex) Macbr., p. 144.

Fig. 10. A group of sporangia, x 10.

_Diderma niveum_ (Rost.) Macbr., p. 137.

Fig. 11. A group of sporangia, x 10.

Fig. 11 _a_. Spore and Capillitium, x 600.

_Prototrichia metallica_ (Berk.) Mass., p. 258.

Fig. 12. A group of sporangia, x 10.

Fig. 12 _a_. Same; capillitium and spores, x 300.

Fig. 12 _b_. Tip of a capillitium thread to show spiral markings and
end-fraying, x 800.

_Comatricha aequalis_ Peck, p. 180.

Fig. 13. A group