138 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 26 



PLATE 16 



Fig. 1. Pleonosporium mexicanum sp. nov. Upper part of a sporangial plant 

 of the type collection, X 25. 



Fig. 2. Tiffaniella saccorhiza (S. & G.) Doty & Menez. Habit of part of a 

 sporangial plant of the type collection, X 37.5 (after Setchell & 

 Gardner) . 



Fig. 3-5. Spermothamnion snyderae Farlow. Fig. 3, A group of developing 

 polysporangia, X 160; Fig. 4. a rhizome showing rhizoids, X 16 

 (both after Smith); Fig. 5, A carpogonial branch X 237. 



