ERYSIBACEAE 21 



(n) Basal and subbasal cell present 



Distichomyces T. 6:308 

 n. Receptacle of a single row Chaetomyces T. 364, L. 504 

 y. Receptacle more or less parenchyma-like, at most only part of the 

 cells superposed in series 

 (x) Appendages all on one side Laboulbenia T. 308, L. 502 

 (y) Appendages on two sides Rickia 16: 68g 

 (z) Appendages completely surrounding the perithecium 



Teratomyces T. 354 L. 502 

 II. Antherozoids exogenous, i. e., produced terminally or laterally on the appendages 

 as naked cells 



1. Receptacle large, very many-celled, parenchyma-like 



a. Perithecium with six wall cells in each row 



(1) Base of trichogyne persistent as a one-celled appendage 



Caenomyces T. 4: 44 



(2) Base of trichogyne not persistent as an appendage 



Zodiomyces T. 371, L. 504 



b. Perithecium with 9-10 wall cells in each row 



Euzodiomyces T. 2: 449 



2. Receptacle of a series of superposed cells 



a. Appendage single Ceratomyces T. 372, L. 505 



b. Appendages several Coreomyces T. 5: 56 



The genus Misgomyces T. 2 : 443 has not been included in the key owing to the 

 fact that its antherids are unknown ; it is very closely related, apparently, to Laboul- 

 benia. 



Order 8. SPHAERIALES 



Mycelium sometimes superficial and abundant, often forming a thallus with algae, 

 but usually scanty and imbedded in the matrix, the threads branched and septate ; prop- 

 agation by means of conidia borne on branches of the mycelium, or by means of 

 pycnidia ; reproduction resulting in a globose, flask-shaped or flattened perithecium, 

 with a round mouth or ostiole except in the simpler forms, in which appendages are 

 also often found; asci usually 8-spored and with paraphyses ; spores hyaline, yellow- 

 ish or brown, one to many-celled. 



Family 15. ERYSIBACEAE 



i: I, 9: 364, 11: 253, 14: 404. 17: 526 

 Mycelium white, cobwebby, superficial, penetrating the epiderm by means of 

 haustoria ; propagation by chains of conidia cut off from upright simple branches ; 

 perithecium without mouth, membranous, regularly with simple or modified appen- 

 dages, often imbedded in the nycelium ; ascus one to several, globose to ovoid, 2-8- 

 spored, without paraphyses ; spores usually i-celled, hyaline. 



Hyalosporae 



Spores i-celled, hyaline 



I. Perithecium with one ascus 



1. Appendages simple Sphaerotheca i: 3 



2. Appendages dichotomously branched Podosphaera i : 2 



