670 MINNESOTA BOTANICAL STUDIES. 



Saccardo separates the dark-colored forms under Acremon- 

 iella. 

 5 species are reported from this country. 



35. ZYGODESMUS Corda. Ic. Fung. 1 : 11. 1837. 

 Hyphae creeping, irregularly branched, with numerous later- 

 al swellings at the septa ("clamp-joints"); conidia muriculate, 

 rarely smooth, simple, borne on denticulations, or solitary on 

 short lateral branches. 



Many of the described species are Basidiomycetes e. g. Z. fus- 

 cus Corda is Tomentella ferruginea Pers. About 14 species are 

 repoi ted from the United States, excluding those that certainly 

 belong elsewhere. 



36. SEPEDONIUM Lk. Obs. Myc. 1 : 16. 1809. 



Light - colored, hyphae all decumbent, branching; spores 

 borne singly or in clusters of 2-3 on the ends of branchlets, 

 echinulate, simple. 



The species which are parasitic on fungi are stages of Hypo- 

 myces. 4 species are reported from the United States. 



37. MYCOGONELk. Obs. Myc. 1: 16. 1809. 



Like the preceding, but spores 1- septate, the upper cell the 

 larger and usually echinulate. 



2 species reported from the United States; stages of Hypo- 

 myces, except M. anceps Sacc, which is the chlamydosporous 

 state of Hydrogera oedipus and should be excluded. 



38. SYNTHETOSPORA Morg. Bot. Gaz. 17:192. 1892. 

 Hyphae all decumbent, branched, intricate; spores borne on 



the ends of short lateral branchlets, each spore consisting of a 

 large opaque central cell with several smaller hyaline cells 

 sunk part way into its surface. 



1 species described; '"a compound 3fycogone." (Morgan). 



Tribe Pericouieae Sacc. Syl. Fung. 4: 269. 1886. 

 Vegetative mycelium sparse or none; sporophores erect, rigid, 

 dark colored, simple or sub- simple; conidia pleurogenous, or 

 borne along the tips of the sporophores on denticulations, 

 simple. 



39. CHLORIDIUM Lk. Obs. Myc, 1 : 11. 1809. 

 Sporophores sub-simple, fuscous; conidia oblong or globose, 



pleurogenous on the upper portion of the sporophores. 



2 species are reported from the United States. 



