THE POLYTRICHACEZ OF WESTERN NORTH AMERICA 313 

Fig. 20. Polytrichum ohioense. 
1 = Moist plant with capsule, X 1. 2=Dryplant,x1. 3=Capsule,X 5. 4= 
Immature capsule with calyptra, X 5. 5 = Peristome, X 150. 6 = Leaf showing 
lamella on upper side, X 15. 7 = Leaf tip, X 65. 8 = Cross section of leaf showing 
lamelle, X 65. 9 = Cross section of a few lamellz showing usual form of marginal 
cells, X 250. 10 = Cross section of a few lamellze just above sheath, X 250. 

and distinctness of the hypophysis. However, all the specimens examined could at 
once be distinguished by the marginal cells of the lamellz. Occassionally in P. ohioense 
they are somewhat depressed in the center approaching forms of P. Commune but the 
elongated capsule clearly separates it from the last. P. ohioense tends to have fewer 
lamelle than P. attenuatum; of the specimens examined none of the former had over 
45, while none of the latter had less than 45. 
