94 MICROTHYRIALES 



b. Asci many, clavate to cylindric; paraphysoids 

 often very like paraphyses 



(1) Asci 8-spored; spores hyaline 



(a) Spores 1-celled Bagnisiella 2:589, 22:407; 20 

 X. Ascoma attached broadly 



y. Ascoma with central innate foot Yoshinagaia 17:860; 20 



(b) Spores x-celled Leptodothiora 24:1265 



(c) Spores muriform Dothiora 8:764; 20 



(2) Asci many-spored; spores hyaline 



(a) Spores 2-celled Hariotia 9:672 



(b) Spores x-celled 



X. Ascoma fungicole Endodothiora 



y. Ascoma not fungicole Sydowia 11:341, 24:964 



(c) Spores muriform Keisslerina 24:1265 



Family 33. MYCOPORACEAE 



Zahlbruckner 92(77) 



Mycelium parasitic on Trentepohlia or Palmella, forming a uniform thallus 

 without a cortex; perithecia reduced to locules in a stroma as in Dothideaceae, to 

 which family the genera might well be referred. 



A. Spores transeptate; algae Trentepohlia 



1. Spores 2-celled 



a. Spores hyaline Chlorodothis 93 



b. Spores dark Sciodothis 93 



2. Spores x-celled 



a. Spores hyaline Nothostroma 93 



b. Spores dark Mycoporis 93 



3. Spores needle-shaped Mycoporellum 93 



B. Spores muriform; algae Palmella Mycoporum 93 



Order 10. MICROTHYRIALES 



Mycelium typically superficial, light-colored or dark, sometimes lacking, often 

 forming an innate hypostroma, more rarely membranous; ascomata or apothecia 

 halved or dimidiate, flat to convex, typically radiate, but only at the margin or not 

 at all in Micropeltaceae, opening by a pore or cleft, or astomous and then splitting 

 irregularly, mostly superficial, occasionally innate or erumpent; hymenium single 

 (polyascous) or several, in this case the asci separated singly or in groups by densely 

 branched threads or tissue masses arising from the hypothecium; asci typically 

 parallel and basal, clavate to cylindric; paraphyses lacking or poorly developed, 

 except in a few genera where they form a typical epithecium, as in the true Dis- 

 comycetes. 



Theissen and Sydow regard this order as belonging to the Discomycetes, 

 though in large part divergent in form, manner of opening and usual absence of 

 epithecium (Ann. Myc. 15:397, 1917). However, it is interesting to know that two 

 years earlier they had included the Polystomellaceae in the Dothideales (Ann. Myc. 

 13:158, 1915). On the other hand, Hoehnel referred a number of the genera to his 

 order Phacidiales (Ber. Deut. Bot. Ges. 35:416, 1917), and placed the Microthyriaceae, 

 together with the Trichothyriaceae, in the Perisporiales (loc. cit.). With the leading 

 students of the group disagreeing so seriously as to its limits and relationships, it 

 is evident that it offers many difficulties to the general worker. However, the 

 scutellum or cover of the apothecium, which is always halved or dimidiate, and 



