766 Proceedings of the Royal Irish Academy. 



Plate XXIX. 



1. Pinnule of Asplenium falcatum^ showing patches of Phycopeltis 



nigra. 



2. End of one of the radiating hies of the thallus, showing the 



larren hairs. 



3. Part of a wider plant, showing two disc-sporangia. 



4. Portion of a disc, showing a round darli area, with a central 



aperture (similar to those regarded hy Mobius and others as 

 probably pycnidia or spermetia, but here apparently acci- 

 dental and due to separation of the thallus from the 

 epidermis, with accompanying decay). 



5. Part of a small-celled plant, with a tendency to break up into 



filaments. 



6. Section of a leaf with the hair-bearing form of Ph. nigra growing 



on the upper surface. 



