Vol.11 Reed. — Tivo New Ascomyeetons Fungi. 161 



Guignardia Alaskana sp. nov. 



Perithecia dark brown or blackish, numerous, scattered irreg- 

 ularly, large, spherical, immersed in the thalli of Prasiola horealis, 

 projecting on both surfaces, 273-450 /* in diameter, vertex 

 convex, pore simple, opening on either surface of the frond. 

 Asci club-shaped with long stalks, eight spored, 25-33 p- long 

 and 7-14 /* wide. Spores narrowly elliptical, with pointed ends, 

 with medium thin walls, hyaline: 8.5-13.5 /^ long, 3-4 i"- wide. 



METHODS. 



For the coarser anatomy and general structure, ordinarj^ 

 razor sections were used, but for the more minute study of the 

 mycelium and perithecial walls it was necessary to embed and 

 section with the microtome. 



I fixed my material, after soaking in sea water, by boiling 

 in a saturated solution of corrosive sublimate a moment, then 

 running up from 50 per cent, into 100 per cent, alcohol, passing 

 through bergamot oil and into paraffine. The sections were 

 2-6 /A thick. 



A water solution of eosiu proved excellent for bringing out 

 the mycelium and the perithecium with its contents. The proto- 

 plasm in the mycelial threads, and in asci or ascospores stained 

 deeply, leaving the cell walls and mycelial walls in distinct 

 contrast. 



The best stain for the finest detail study is the iron ha?ma- 

 toxylin which brings out the mycelia and pseudoparenchyma of 

 the perithecium very distinctly. 



Thionin, anilin blue and Congo red were also used for stains, 

 but they were not very satisfactory. 



