264 The Scottish Naturalist. 



A. Pycnidia nearly smooth. 



Pycnidia somewhat cup-shaped, discoid, often imperfect, 



subcutaneous. Discula. 



Pycnidia bursting by valves. Sporonema. 

 A. A. Pycnidia pilose or setose. 



Sporidia without appendages. Amerosporium. 



Sporidia with a bristle at each end. Dinemasporium. 



Hyalodidym^e Sacc. 

 Sporidia oblong or ovate, 2-celled, hyaline. Discella. 



Phragmospor/e Sacc. 

 Sporidia oblong or elongate, 2-pluriseptate. Pilidium. 



XXXIII. Discula Sacc. 



Pycnidia disciform-saucer-shaped, often imperfect, as if formed 

 from the altered matrix, covered with the epiderm, which 

 is at length torn into shreds ; sporidia ellipsoid, oblong, 

 or cylindrical, one-celled, hyaline. 



183. D. microsperma (B. & Br.) Sacc, 3571, C.585, M.1171 



(sub Discella microsperma) (D. Jerdon). 

 On dead twigs of Willow. 

 Tweed (Jedburgh). 



XXXIV. Sporonema Desm. 



Pycnidia subcutaneous, then erumpent, at first closed, then 

 splitting from the centre outwards into several divisions; 

 central mass discoid, rather soft, often of a different 

 colour from the rest ; sporidia ovoid or cylindrical, 1- 

 celled, hyaline, basidia filiform, often branched. 



184. S. Obturatum (Fr.) Sacc. 3588, C.588, M.i 108 (sub 



Clinterium obturatum Fr.), (D. Carmichael). 

 On leaves of Calluna vulgaris (Ling), at Appin. 

 Argyle. 



XXXV. Amerosporium Speg. 

 Pycnidia subcupulate, setulose ; sporidia cylindraceo-elliptical. 



185. A. macrotrichum (B. & Br.) Sacc, 3602, C.593, S.M., 



2179 (sub Excipula macrotricha Br. & Br.) (D. Keith, 

 in Scot. Nat., 1881, p. 118). 

 On broom-sticks (and Whins in England) in March. 

 Moray (Forres). 



