266 The Scottish Naturaltst. 



coloured ; sporidia growing on basidia of various forms 

 (which are sometimes obsolete), supported on a more or 

 less developed proligerous stratum. 



Analytical key to genera. 



HYALOspoRiE Sacc. 



Sporidia globose, ovoid or oblong, or shortly cylindrical, one- 

 celled, hyaline, or rarely a little coloured. 

 Pustules long subcutaneous, grey or pale, on leaves or 

 stems ; sporidia solitary. Glceosporium. 



ScOLECO-ALLANTOSPORiE SaCC. 



J poridia cylindrical, filiform or sausage-shaped, one-celled, 

 hyaline or nearly so. 

 Pustules subcutaneous, effused, on living leaves, white or 

 pale ; sporidia filiform, often flexuous. 



Gylindrospori'ii m . 



Pustules variable in form, often brightly coloured ; sporidia 



filiform-falcate. Libert e 1 la. 



Ph/Eospor^e Sacc. 



Sporidia globose, oblong or elongate, one-celled, sooty or olive- 

 brown. 

 Sporidia growing singly on tips of basidia, globose or oblong. 



Melanconium. 



Didymospor^e Sacc. 



Sporidia ovoid, subfusiform, or oblong, i-septate, 



Sporidia fuscous ; on decaying matters, Didymosporium. 

 Sporidia sub-hyaline ; on living leaves. Marso?iia. 



Ph^ophragmi^e Sacc. 



Sporidia 2-or-more septate, sooty brown. 

 A. Sporidia oblong. 



Pustules subcutaneous ; sporidia escaping in tendrils. 



Stilbospora* 

 Pustules erumpent ; sporidia never escaping in tendrils. 



Coryneutn. 

 AA. Sporidia stellate-lobed, pluri-septate. Asterosporium. 



Dictyospor.e Sacc. 



Sporidia oblong, pyriform or rhomboid, pluri-septate, muriform, 

 fuscous. 



