scattered over the principal segments. The sori are very small, and crowded 

 in the ultimate segments. The older parts of the frond are a dark brown- 

 red, the younger pinky ; all become darker, and sometimes very dark, in 

 drying. The frond very imperfectly, and with difficulty adheres to paper 

 in drying. The spore-threads are very much branched. 



This species is nearly allied to N. affine, as a variety of which 

 I formerly regarded it, but have been induced to separate it 

 specifically on account of its very rigid substance. N. affine is 

 delicately thin, and closely adheres to paper. This is also darker 

 in colour ; and but for its much divided and deeply cut frond 

 would come near N. Gunnianum. 



The first specimens I received of it were in a parcel sent to 

 me in 1851 by Dr. Curdie, of Geelong, to whom this species is 

 dedicated. 



Fig. 1. NiTOPHYLLUM CuRDiEANUM, — the natural size. 2. A fragment of a 

 segment, bearing cystocarps, — slightlij enlarged. 3. Section through a cys- 

 tocarp. 4. Spore-thread. 5. Frustule, with sori. 6. Tetraspores, — vari- 

 ously maguijied. 



