Perichaena 263 



the sporangia will resemble those of Trichia contorta. The smaller 

 developments below bark have sporangia with usually more or 

 less distinct lids. Numerous intermediate forms connect P. corti- 

 calis with P. depressa and these may be observed in many colo- 

 nies. In all such forms the characters of the capillitium and 

 spores are very variable, and critical separations cannot be made 

 on them alone without considering the sporanglal shape and wall. 

 The yellow area of dehiscence seen in P. depressa is rarely, if ever, 

 present in P. corticalis. It is possible that some of these inter- 

 mediate forms are hybrids between various species of the genus. 

 On a small log at Jericho, Long Island, were found the following 

 forms, all in the same stage of perfect maturity; P. chrysosperma, 

 P. corticalis and var. liceoides, P. depressa, P. minor and var. 

 pardina, together with numerous other variations in size, shape 

 and capillitium. P. marginata is a phase with crystalline lime 

 on the wall. Such forms are frequent in this as well as other 

 species of the genus Perichaena, and the presence of lime is of no 

 importance as a specific character. 



4. Perichaena minor (G. Lister) Hagelstein, Mycologia 35: 130. 

 1943. 



Hemitrichia minor G. Lister, Jour. Bot. 49: 62. 1911; Mycetozoa ed. 3. 220. 

 1925; Macbr. & Martin, Myxomycetes 299. 1934. 



Plasmodium watery cinnamon (Lister). Sporangia sessile or 

 stalked, scattered or united in pairs, globose to subglobose, or 

 forming curved plasmodiocarps, 0.2 to 0.5 mm. diam., dull yellow 

 or yellowish brown; sporangial wall membranous, pale yellow, 

 translucent, minutely papillose or marked with faint curved lines 

 of thickening, and with scanty superficial deposits of refuse mat- 

 ter. Stalk when present black, cylindrical, enclosing dark refuse 

 matter, 0.1 to 0.2 mm. high. Capillitium a loose network of 

 yellowish threads 2.5-4 n diam., irregularly constricted and with 

 large, bulbous expansions; free ends few or many, often swollen; 

 threads of the capillitium studded with numerous small spines, 

 often arranged in quincunx, and presenting the appearance of 

 diagonal lines when observed with insufficient numerical aperture. 

 Spores pale yellow, faintly warted, 9-11 /x diam. 



Var. pardina (Minakata) Hagelstein, Mycologia 35: 131. 1943. 

 Hemitrichia minor G. Lister var. pardina Minakata; G. Lister, Trans. Brit. 

 Myc, Soc. 5: 82. 1915. 



