W. C. Sturgis — Type- Specimens of Myxomycetes. 467 



Cbaterium obovatum, Pk., Rep. XXVI, p. 75, ISYS. This species 

 requires but little comment. It is a perfectly typical specimen of 

 Badhamia rubiginosa, Rost., and is so referred by both Lister 

 and Macbride. The spores are of the normal type characteristic of 

 Lister's var. genuina. 



Physarum albicans, Pk., Rep. XXX, p. 50, PL II, figs. 5-8, 1877. 

 The very scanty type-specimen shows a few scattered sporangia, 

 globose, pure white, and borne upon delicate, white stalks charged 

 throughout with lime. The capillitium is yerj delicate but persist- 

 ent, retaining the form of the sporangium after the wall of the latter 

 has disappeared ; it arises from a small, hemispherical or slightly 

 conical, white columella. The lime-knots are small, whitish and 

 fusiform or round. The spores are bright violet-brown, almost 

 smooth, and measure 7.5-8.4/a in diameter. (PI. LX, fig. 9.) These 

 are so evidently the characteristics of Physarmn glohidiferum, Pers., 

 that there can be no hesitation in referring the specimen to that 

 species, as is done by Lister and Macbride. The only peculiarity 

 about the specimen is seen in the slightly swollen bases of the stalks, 

 filled with large, globular masses of lime and refuse matter which 

 readily separate from the enclosing wall of the stalk. (PI, LX, fig. 8.) 



Physarum albicans, var. subroseum, Pk. {Didymiwn snhroseum, 

 Pk.), Rep. XXVIII, p. 54, 1875; Rep. XXX, p. 50, 1877; Rep. XXXI, 

 p. 55, 1878. A single small specimen of this form accompanies the 

 type-specimen of P. albicans, Pk. Professor Peck considered it as a 

 variety of that species on account of "the pinkish tinge of the perid- 

 ium." This feature is not now apparent and the so-called variety 

 should be merged with the species. 



Physarum atrorubrum, Pk., Rep. XXXI, p. 40, 1878. The type- 

 specimen of this most beautiful species is rather scanty, but is quite 

 suflUcient for acciirate determination. Lister and Macbride agree in 

 referring it to P. prdcherrlmiun, B. & R., and notwithstanding 

 the meagre character of the original description of that species and 

 the apparent absence of any specimen of it, the words '■'■ stipitebrein 

 purpureo; p>eridlo globoso floccisque Ulacinis,^'' apply so perfectly to 

 the species described by Peck and to no other with which we are 

 acquainted, that we can but conclude that the two species are iden- 

 tical. The color of Peck's type-specimen is almost exactly that of 

 Dlctydiuni umbilicatum, Schrad. The original description of the 

 species, repeated by Macbride (N. A. Slime Moulds, p. 49), is thor- 

 oughly adequate and covers the main features observed in the tj'pe- 

 specimen. 



