MOSSES WITH A HAND-LENS 55 



more abundant southwards, being comparatively rare in New 

 England. The Northern Leucodon has gradually acuminate 

 leaves, which are somewhat secund and turned towards the lower 

 side of the branch. Its capsules are partially immersed. 



The Southern Leucodon has terete julaceous branches, leaves 

 smaller and abruptly acute, and capsules entirely free from the 

 perichrctial leaves. 



THE WATER MOSSES (Fontinalis) 



ALTHOUGH mosses belonging to several other families are 

 aquatic, the mosses of the Fontmalis Family are most em- 

 phatically entitled to the name of The Water Mosses. 

 In the genus Fontinalis all the species are aquatic and submerged. 

 Some grow attached to stones and sticks in swift brooks. Others 

 are found attached to objects in ponds and sluggish streams. 

 Rarely, if ever, are they found in stagnant water. The Water 

 Mosses are so distinct from all others in their long slender float- 

 ing stems and branches that no one can fail to recognize them. 

 The species are, however, very difficult to determine, with one 

 or two exceptions. 



The Giant Water Moss {Fontinalis gigdntea Sulliv. ) is 

 common in cool brooks and is most distinct by reason of its large 

 turgid three-cornered stems and branches. The branch shown in 

 the plate is a very short one ; the branches are sometimes a foot 

 or more long, The Giant Water Moss rarely fruits, but the Com- 

 mon Water Moss (Fontinalis dalecdrlica B. & S. ) is every- 

 where abundant and usually fruits freely, the capsules maturing 

 in summer. As will be seen from the plate, the capsules are 

 almost entirely covered by the pericructium and are borne on the 

 older portions of the plant from which the leaves have fallen. 

 One must not be too sure that he has found this species until he 

 has studied it with a compound microscope, as there are several 

 other common species that are not readily distinguished from it. 



