perichaena] aFvCyriaceae 253 



5. P. vermicularis Rost. Mon., App. p. 34 (1876). 

 Plasmodium watery-white or yellowish-white. Sporangia 

 scattered, sessile, globose on a narrow base, 0-5 mm. diam., 

 or forming slender curved or net-like plasmodiocarps, 

 ochraceous-yellow, pale umber or greyish ; sporangium-wall 

 of two layers, the outer more or less charged with dark granules 

 and occasionally with angular crystals of lime, closely com- 

 bined with the membranous papillose inner layer ; in some 

 cases the outer layer is not distinguishable in the upper part 

 •of the sporangium. Capillitium a profuse network of sparingly 

 branched yellow threads, 2 to 4 /a diam.. rough with minute 

 scattered warts and irregular constrictions. Spores yellow, 

 minutely warted, 10 to 15 ^ diam. — Physarum vermiculare 

 Schwein. in Trans. Amer. Phil. Soc, n.s. iv. 257 (1832). 

 Ophiotheca pallida Berk. & Curt, in Journ. Linn. Soc, x. 350 

 (1869). 0. zimbrina Berk. & Curt, in Grev., ii. 68 (1873). 

 0. vermicularis Mass. Mon., 134 (1892) ; Macbr. N. Am. Slime- 

 Moulds, 181. 0. reticulata Mass. I.e., 133. Licea reticulata 

 Berk. & Br. in Journ. Linn. Soc, xiv. 86 (1873). Perichaena 

 variabilis Rost. Mon., p. 295 (1875) ; Lister Mycetozoa, 199 ; 

 Petch in Ann. Perad., iv. 370. P. Friesiana Rost. I.e., 

 p. 296. P. reticulata Rost. Mon., App. p. 35. P. confusa 

 Mass. I.e., 117. 



Var. pedata Lister in Journ. Bot., xlii. 139, t. 459, figs. 

 3a, b (1904) ; sporangia scattered or in small clusters, sub- 

 globose, pale nut-brown or ochraceous-brown, stalked ; stalks 

 blackish- brown, rugose, 0-1 to 0-3 mm. high. 



Hob. On leaves and bark. 



PI. 187. — a. sporangia ; b. capillitium ; c capillitium and spores with fragment of 

 sporangium-wall ; (England). 



The yellow form of this species has appeared in some abundance 

 on leaves and twigs in successive years at Lyme Regis, and corresponds 

 exactly with the type specimen of Physarum vermiculare from Schweinitz 

 (K. 1671). The type of Ophiotheca umbrina Berk. & Curt, from North 

 Carolina no. 413 (K. 1705), was originally published as Ophiotheca 

 pallida Berk. & Curt. It is a pale umber plasmodiocarp form, agreeing 

 in the structure of the sporangium-wall, capillitium, and spores with 

 the English gatherings. Part of this type was sent by Fries to 

 Rostafinski, who described it as "Perichaena Friesiana'' (Rost. Mon. 

 p. 269) ; in the appendix to his Monograph, however, Ophiotheca 

 umbrina B. & C. is placed as a synonym for P. variabilis Rost. ; 

 it was probably by an oversight that Rostafinski still retained 

 P. Friesiana as a distinct species (Mon., App. p. 35). A speci- 

 men from New Jersey from Ellis, no. 726, N. Am. Fungi 

 (K. 990), originally named P. Friesiana, and then O. umbrina, 

 resembles the Lyme Regis gathering and Rostafinski's description of 

 P. vermicularis ; these specimens from New Jersey and from Lyme 

 Regis are given as the types of a new species, P. confusa, by Massee, 



