DOTHIDEALES 295 



Orton, 1924). If one wishes to regard it as derived, one must consider 

 it as transitional to the Montagnellaceae. If one regards it as primitive 

 it must be connected to the Mycosphaerellaceae. Which of these two 

 concepts is more justified, is still uncertain. 



Montagnellaceae. — As an appendix, a third family is considered 

 (Theissen and Sydow, 1915) whose content and limits subsequent dis- 

 cussion must settle. Some of their representatives remind one of the 

 simpler Phyllachoraceae without stromata and clypeus; others (as the 

 higher species of Botryosphaeria) possess a well-developed stroma which 

 encloses single asci (in contrast to the several asci of Botryosphaeria) 

 in columnar outgrowths. The latter forms, as the Rosenscheldia group, 

 are probably derived from the Dothideae or Pseudosphaeriaceae; the 

 former, as the true Montagnelleae, probably by the loss of the clypeus 

 from the Phyllachoraceae. As the majority of their forms are tropical, 

 probably an ontogenetic study will not be made for a long time. 



