Rostafinski distinguished this beautiful species by the color of the peridium and the conic columella. According to Mr. Lister, Rostafinski was not specially careful in labelling his material, different forms having been included under this specific name. Nevertheless, the description is well drawn, and excludes _L. physaroides_ completely. At all events our American specimens correspond so well with the description of _L. columbinum_ (Pers.) Rost. that there seems no doubt that we have here what the Polish author figured and described, whether or not he was always consistent in applying his labels. The color distinguishes at sight the present species from _L. physaroides_, and the capillitium and large rough brown spores distinguish it from _L. violaceum_. The capillitium of the minute _L. scintillans_ is much denser and more rigid, and the spores smaller. The stipe when dry is ciliate. This is the common species of our western mountains, especially on the Pacific slope. In the Cascades every dark ravine is certain to show it in later summer and autumn, far extended colonies covering the moist surfaces of every mouldering log; the myriad globoid sporangia giving back when brought to the sunlight the most extravagant blues and greens with all the splendor of metallic sheen, their brilliant beauty never fails to quicken the attention of even the most insensate tourist. Abundant in the western forests, in the east extremely rare; Maine, Pennsylvania, South Carolina, Washington, Oregon; Vancouver, Canada. 4. LAMPRODERMA SCINTILLANS (_Berk. & Br._) _Morg._ PLATE V., Figs. 2, 2 _a_. 1877. _Stemonitis scintillans_ Berk. & Br., _Jour. Linn. Soc._, XV., p. 2. 1877. _Lamproderma arcyrioides_, var. _iridea_ Cke., _Myx. G. B._, p. 50. 1892. _Lamproderma irideum_ (Cke.) Mass., _Mon._, p. 95. 1894. _Lamproderma scintillans_ (Berk. & Br.) Morg., _Jour. Cin. Soc._, p. 47. Sporangia gregarious, scattered, globose or depressed-globose, rich metallic blue or purple, iridescent, stipitate; the stipe long, slender, even, inclined and nodding or sometimes erect; hypothallus small, circular; columella cylindric, small, not reaching the centre, black; capillitium dense, of rigid, straight, sparingly branched or anastomosing, brown threads, which are sometimes white or colorless just as they leave the columella; spores globose, rough, violaceous brown, 8 mu. This is _L. irideum_ of Cooke and of Massee's _Monograph_. Its capillitium is remarkable, and constitutes an easy diagnostic mark. The threads appear at first sight entirely simple, but are really several times furcate, and not infrequently anastomose. The spores are covered with sparsely sown large papillae, easily seen under moderate magnification. This is one of our earliest species. To be sought in May on beds of decaying oak leaves in the woods, especially in wet places, near streams, etc. Rare. New England, Pennsylvania, Ohio, Iowa.