Plasmodium scarlet. Sporangia globose or cylindric, sessile or sometimes narrowed to a stem-like base as if short-stipitate, olivaceous brown with sometimes a flush of red; the peridium simple, thin rugulose or plain, the calcareous scales few, or apparently included; columella none; capillitium dense, the nodules rather large, angular, rusty brown; spores dull violaceous, gently roughened, about 10 µ.

A beautiful well-marked species, but evidently rare in North America. Our only typical specimens are from the gatherings by Mr. Wingate, part of which is by Lister referred to this species, Mycetozoa, 2nd ed., p. 82.

P. rubiginosum Fr. in the N. A. S., 1899, is based on certain west coast specimens now known as Badhamia decipiens Berk.

In Colorado there occurs a plasmodiocarpous form of the species. It has the characteristic spore and capillitium but in form and habit differs very decidedly. The fructification is a delicate netted plasmodiocarp, the tubule about .5 mm., bright red; the peridium simple, cartilaginous, dehiscent from above, and flecked with just here and there a red calcareous scale.

Collected at Palmer Lake; Professor Bethel.

16. Physarum instratum Macbr. n. s.

Sporangia very small, closely crowded on a delicate, more or less visible hypothallus, often connate, but not superimposed, sub-spherical, dull orange, brownish or tawny; peridium thin, violaceous, covered with very minute yellow calcareous scales; columella none; capillitium lax, sometimes almost wanting; the nodules small, yellowish or brownish, occasionally confluent; spore-mass violaceous, spores by transmitted light, violet-tinted, smooth or nearly so, 6–7 µ.

Not uncommon in the Mississippi valley, where it sometimes is passed by the collector as an immature form of some other species. The appearance is very characteristic, unlike P. virescens in both habit, size, and color. Colonies are quite often three inches in length. The most common habitat seems to be rotten oak, especially fragments of charred logs, etc.