Explanation of Plate II.— a. Fruiting Polytrichum com- 

 mune x i, dry. b, The same moist with the calyptra removed, 

 c, Leaf of the same X 10. d, Capsule of the same x 5- e, Capsule 

 of P. Ohioense X 5- f. Male plant of P. commune x i. g and 

 h, P.ptizferum, dry and wet, x i. o, Leaf of P. juniper inum 

 X io. 6, Portion of the same X 30. p, Leaf of P.piliferum X 10. 



