23. PHYSARUM MURINUM _Lister_. 1894. _Physarum murinum_ Lister, _Mycetozoa_, p. 41. 1899. _Physarum ravenelii_ (Berk. & C.) Macbr., _N. A. S._, p. 48. 1911. _Physarum murinum_ Lister, _Mycetozoa, 2nd ed._, p. 50. Sporangia scattered, globose or perfectly spherical, ashy-brown, rugulose, stipitate; stipe elongate, pale brown, erect, generally tapering upward, calcareous, brittle; hypothallus none; columella short, hemispherical or bluntly conical; capillitium dense, much as in _P. globuliferum_, the calcareous nodules, umber, brownish or orange-yellow, small; spore-mass brown; spores by transmitted light, bright lilac, almost smooth, 7-9 mu. A very distinct species, easily known by its peculiar drab-colored peridium and dull brown stalks. The author of the species allows for the capillitial nodes none other tint but brown. Under direct illumination many gatherings, especially where the sporangia are well blown out, show nodules of a bright orange tint. Not rare in the eastern United States, to Missouri and Iowa. Reported also from western Europe. Mr. Lister finds _Didymium ravenelii_ Berk. & C., on which _P. ravenelii_ (Berk. & C.) Macbr. is founded, referable to _P. pulcherripes_ Pk. 24. PHYSARUM PULCHERRIMUM _Berk. & Rav._ 1873. _Physarum pulcherrimum_ Berk. & Rav., _Grev._, II., p. 65. 1875. _Physarum pulcherrimum_ (Berk. & Rav.) Rost., _Mon._, p. 105. 1879. _Physarum atrorubrum_ Peck, _Rep. N. Y. Mus._, XXXI., p. 40. 1899. _Physarum pulcherrimum_ Berk. & Rav., Macbr., _N. A. S._, p. 49. 1911. _Physarum pulcherrimum_ Berk. & Rav., Lister, _Mycetozoa, 2nd ed._, p. 50. Plasmodium dark red. Sporangia scattered or gregarious, globose, even, or somewhat wrinkled, dark red, stipitate; stipe cylindric, even, sub-concolorous or blackish; columella small or none; capillitium free from spores, whitish, with a slight pinkish tinge; spores dark brown in mass, dark red when separated, globose, smooth, 7.5-8.5 mu. The capillitium is very delicate, and when cleared of spores the knot-like thickenings are seen to be very small and of a dark red color, to which is probably due the pinkish tinge which marks the whole. A part only of the thickenings are filled with lime granules. The dark red granules of the sporangium walls are abundant and appear to form a continuous crust. This is _P. atrorubrum_ Peck, and his description, _l. c._, has been closely followed. The very brief description in _Grevillea_, however, antedates the New York publication and, all inadequate as it is, no doubt applies to the same thing. Not rare. New York, Pennsylvania, Ohio, Missouri, Iowa. 25. PHYSARUM PULCHERRIPES _Peck._