This is _Badhamia hyalina_ (Pers.) Berk., Rost., _Mon._, p. 139; but Rostafinski himself admits that the two species, here united, as he defined them, are very much alike, having "the same spores and capillitium", differing in the form of the sporangium, an inconstant feature. Bulliard's name has precedence; his descriptions of this and the preceding species are remarkable. The peculiarly adherent spores distinguish the species from _B. utricularis_; and the sporangia sessile or with short but strand-like stipes, distinguish it from _B. papaveracea_. The description above is for the typical European form. Lister expresses doubt whether this occurs in the United States. The form from Iowa which is the basis for the inclusion of the species in N. A. S. is, we believe, nothing else than _B. capsulifera_ (Bull.) Berk. The form approaches _B. populina_ as this is presented in Colorado. The Iowa specimens are white, aggregate, superimposed, etc., but have the capillitium and spores exactly as described for the type. Accordingly _B. populina_ as this occurs in Colorado has been for years referred to the Berkeley species. The thicker more strongly calcareous peridia constitute, as would appear, the principal difference in the forms from Colorado. See next species. 13. BADHAMIA POPULINA _List._ 1904. _Badhamia populina_ List. _Jour. Bot._, XLII., p. 129. 1911. _Badhamia populina_ List. _Mycetozoa, 2nd ed._, p. 32. Plasmodium white; sporangia sessile, crowded, heaped, large, 1.5 mm., rarely stipitate, globose or ovoid, white; stipe when present brown; capillitial strands broad, calcareous; spores clustered, 16-20 in a cluster, purple-brown, roughened and sometimes marked by obscure ridges and bands, 10-12 mu. Generally distinguishable by its unusually large calcareous, white sporangia. The peridia are strongly calcareous, shell-like in texture. In some cases the color is tinted with rose. This species is very near _B. capsulifera_ as recognized in the United States. When white the Colorado material corresponds almost exactly with the forms collected in Iowa, and regarded as representing the species just named. The Colorado gatherings are more strongly calcareous and the spores sometimes present the variations named. "The Colorado phase of the American form." Colorado,--_Bethel_. Europe? 14. BADHAMIA PAPAVERACEA _Berk. & Rav._ PLATE IX., Figs. 6, 6_a_, and 6_b_. 1873. _Badhamia papaveracea_ Berk. & Rav., _Grev._, II., p. 66. 1894. _Badhamia hyalina_ var. _papaveracea_ Lister, _Mycetozoa_, p. 30. 1899. _Badhamia papaveracea_ Berk. & Rav., Macbr., _N. A. S._, p. 69. 1911. _Badhamia papaveracea_ Berk. & Rav., List., _Mycetozoa, 2nd ed._, p. 32.