The Horn-tooth Mosses 



The mature spore-cases are long-egg-shaped, erect or slightly 

 arched, with a short neck. They are dark or pale-red with wine- 

 red or yellow pedicels, and short-beaked, conical lids, becoming 

 deeply furrowed, inclined, and contracted below the mouth 

 when old. 



Leaf. 



Pel'tca. 



C. purpureum. 



There is but one row of teeth, each tooth being cleft into two 

 equal and strongly jointed segments, which suggest the generic 

 name Ceratodon, a compound of two Greek words, fcepa<;, Keparo?, 

 a horn, and 6Sa>v, a tooth. The two characteristics by which one 

 may feel sure that his 

 moss is a horn-tooth, 

 are the cleft teeth and 

 the shape and groov- 

 ing of the spore-cases. 



There are eighteen 

 species in all, one 

 common in North 

 America. 



The Purple 

 Horn-tooth Moss, 

 Ceratodon purpureum, 

 Brid. See Colour 

 Plate IV. 



Habit and "habitat. Look for the Purple Horn-tooth Moss on 

 rocky ledges in open sunny places of the woods, in pastures and 

 along roadsides, and in vacant city lots. Bright-green cushions 

 of this moss may be found in depressions of the rocks during 



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