BARNES NORTH AMERICAN MOSSES. 185 



II. Costa scabrous or lamellose at back. 



leaves with pellucid hair points .... C. introflexns, 78. 

 Leaves not hair pointed. 



Alar cells round, lamina wanting . . . C. frigidus, 79. 



No auricles ', . . . . * . C. Yirginicus, 80. 



FISSIDENS, p. 81 (incl. Conomitrium, p. 89. 1 ) 



1. (EUFISSIDENS.) Plants terrestrial or submersed but not float- 



ing; leaves soft, one layer of cells. 



A. Fruit terminal. 



i. Monoicous, male flowers axillary. 

 [F. falcatulus may be sought here.] 



Leaf -cells small, densely chlorophyllose, in distinct rows F. limbatus, 82. 

 Leaf -cells large, not densely chlorophyllose, nor in dis- 

 tinct rows F. bryoides, 81. 



2. Dioicous or monoicous with the male flowers terminal on a root- 



ing branch at the base of the female stem. 



a. Leaf-cells l-2 times as long as wide, large, distinct. 



Plants less than 1 mm. high, leaves two or three pairs F. Closteri, 81. 

 Plants 2-4 mm. high, wholly hyaline, leaves 3-5 pairs F. hyalinus, 84. 



b. Leaf-cells almost or quite isodiametric, often obscure. 



[F. limbatus may be sought here.J 



Leaves with a narrow border, at least on vaginant lamina. 

 Marginal leaf -cells not papillose. 

 Leaves acute, costa percurrent. 

 Vaginant lamina not reaching middle of leaf, peris- 

 tome arising below the mouth . . . . F. pnsillus, 94. 

 Vaginant lamina reaching middle of leaf, peristome 



not arising below the mouth F. incnryus, 2 82. 



Leaves obtuse, costa vanishing below apex F. obtusifolius, var. 95. 



1 See Barnes: Bot. Gaz. 12: 1. 1882. 

 4 See Appendix, no. 93. 



