Fig. 5. Sporangia, the first closed, x 10. _Physarum sinuosum_ (Bull.) Weinm., p. 52. Fig. 6. Plasmodiocarp, natural size; 6 _a_, x 4; see also Plate XIX., Fig. 15. _Physarum virescens_ Ditmar, p. 61. Fig. 7. Groups of sporangia, x 3 and x 8. Fig. 7 _a_. Spores, x 750. _Physarum viride_ Pers., p. 98. Fig. 8. A single sporangium, x 25; 8 _a_, reverse. Fig. 8 _b_. The same after spore-dispersal. Fig. 8 _c_. Capillitium, x 750. [Illustration: PLATE VIII] EXPLANATION OF PLATE IX _Physarum didermoides_ (Ach.) Rost., p. 78. Fig. 1. Sporangia, x 15. Fig. 1 _a_. A single sporangium open; shows calcareous capillitium, x 15. Fig. 1 _b_. Spores, x 900. _Physarum notabile_ Macbr., p. 80. Fig. 2. A cluster of sporangia, x 15. Fig. 2 _a_. A single sporangium open, x 15. Fig. 2 _b_. Spores, x 900. See also Plate XV., Figs. 2, 2 _a_, and the frontispiece. _Physarum contextum_ Pers., p. 56. Fig. 3. A group of sporangia, x 15. Fig. 3 _a_. Spores of the same, x 600. _Physarum cinereum_ (Batsch) Pers., p. 59. Fig. 4. A group of sporangia, x 4. Fig. 4 _a_. A single sporangium, x 20. Fig. 4 _b_. Capillitium of the same, x 240. Fig. 4 _c_. Spores, x 450. _Physarum albescens_ Ellis, p. 86. Fig. 5. Sporangia, x 5. See also Plate XVI., Figs. 4 and 4 _a_. Fig. 5 _a_. Spore of the same species, x 450. Fig. 5 _b_. Capillitium of the same, x 240. _Physarum serpula_ Morg., p. 49. Fig. 6. Plasmodiocarps, about natural size. Fig. 6 _a_. A bit of the plasmodiocarp, showing structure, x 6. Fig. 6 _b_. A spore of the same species, x 1400. _Physarum leucopus_ Link., p. 79. Fig. 7. A single sporangium, x 15. Fig. 7 _a_. A spore of the same species, x 900. Fig. 7 _b_. A fragment of the capillitium. [Illustration: PLATE IX] EXPLANATION OF PLATE X _Badhamia rubiginosa_ (Chev.) Rost., p. 43. Fig. 1. A group of sporangia, x 5. Fig. 1 _a_. Two sporangia, same species, x 18, to show persisting capillitium. Fig. 1 _b_. Capillitium fragment, x 240. Fig. 1 _c_. Spore of the same species, x 750. _Fuligo septica_ (L.) Gmel.; form _laevis_, p. 29. Fig. 2. An aethalium, natural size. Fig. 2 _a_. A section of the same, x 10. Fig. 2 _b_. A spore of the same, x 750. _Fuligo cinerea_ Pers., p. 26. Fig. 3. A small aethalium borne upon a blade of grass, natural size. See also Plate XXIII. Fig. 3 _a_. Capillitial fragment from the same specimen, x 450. Fig. 3 _b_. Spores of the same, x about 750. _Didymium minus_ List., p. 121. Fig. 4. A single sporangium, x 25. Fig. 4 _a_. The capillitium and fragment of the peridium of the same species, x 380. Fig. 4 _b_. A spore of the same species, x 1000. _Trichia iowensis_ Macbr., p. 269. Fig. 5. Tip of an elater, x 1400. See also Plate III, 3, 3 _a_, 3 _b_. _Badhamia papaveracea_ Berk. & Rav., p. 42. Fig. 6. Sporangia, a cluster, x 8. Fig. 6 _a_. A cluster of spores, x 400. Fig. 6 _b_. A single spore of the same, x 1400. _Reticularia lycoperdon_ Bull., p. 210.