34 ILLINOIS BIOLOGICAL MONOGRAPHS [200 



is made distinctive of the Polystomellaceae by Theissen and Sydow". 

 Moreover the mode of origin of the perithecium by anastomosis of many 

 fine mycelial threads is not characteristic of the Microthyriaceae or of the 

 Dothideales. 



The peculiar mycelial characters shown are also characteristic of neither 

 of the above named groups. The stromata are Dothideaceous in character 

 in that several locules occur in one stroma each locule without a definite 

 individual perithecial wall; but the mycelium and the appearance of the 

 fungus in general deny relation with the Dothids. 



If uniloculate stroma were present there would be no hesitation in 

 placing the fungus in the Capnodiaceae. Pluriloculate stromata in the 

 Capnodiaceae seem somewhat anomolous but are not necessarily so. 

 While this fungus typically has many locules, instances are seen with 

 only one locule. The gelatinous mycelium and the abundant gelatinous 

 paraphyses suggest kinship with the Capnodiaceae and it is in this group 

 that I place it. 



There is sufficient resemblance between this fungus and Chaetoplaca 

 memecycli Syd." to make it appear that the two may belong in the same 

 family though they clearly do not belong to the same genus owing to the 

 well defined locules in my fungus, such locules being absent in Chaetoplaca. 

 There are also very essential dififerences in the spore structure. Sydow in 

 his first publication placed his fungus in the Hemisphaeriaceae though 

 latter Theissen and Sydow"* suggest that it be regarded as a borderland 

 form between the Hemisphaeriaceae and the Discomycetes though they are 

 in doubt whether the whole ascogenous layer represents a disc or whether 

 the structure should be regarded as representing numerous locules each 

 with one ascus. 



CLYPEOSPHAERIACEAE 



Stegastroma Sydow. 

 Ann. Myc, 14:81, 1916. 



47. Stegastroma guianense Stevens s. p. 

 [Figures 88, 89] 

 Spots small, often on the base of the leaflets, pale yellow, bearing 

 several scattered perilhecia. Clypeus only in the upper surface, about 30 

 to 145m thick and only about 100 to 200^ across. Locules 150 to 260/u in di- 

 ameter, 170m deep, ostiole through the clypeus, (7m). Asci 8-spored, 87 x 

 25m. Paraphyses few, filiform. Spores inordinate, pale and continuous 



" Die Dothideales. Ann. Jlyc, 13:149, 1915. 



" Sydow, H. & P. Beitrag zur Kenntnis der PilzcQora der Philippinen-Inseln. Ann. 

 Myc, 15:232, 1917. 



•' Theissen and Sydow, Syn. Taf . I. c. 



