CYSTOCOLEUS. 259 



goniwm in its erectish habit of growth, but agreeing with that 

 generally in the axial cells, the greenish colour of the content of 

 which is also supposed to be due to chlorophyll, as the cells 

 therefore to correspond also with gonidia. But the thread-cells 

 with colourless content which, as in Ccenogonium, surround the 

 central ones, are few (4-6) in number, and dark-brown, and 

 coalesce into a sheath. The only species is C. rupestris (Pers.) 

 Rabenh. (Racodium rupestre (Pers.) Fr. Cystocoleus ebeneus, 

 Thwaites I infra cit.) which inhabits rocks, and has occurred in 

 North Carolina, M. A. Curtis ; in Pennsylvania, Wolle; and in 

 Ehode Island, Farlow. 



Besides Thwaites (Ann. Mag. Nat. Hist. 2, 3), De Bary 

 (Morph und Phys. der Pilze, etc., p. 270), and Schwendener 

 (Untersuch in Naeg. Beitr. 4, p. 173) have described the plant. 



