HYP XI. I. 93 



Monoicous; forming dense tufts of a deep dull green, often 

 spreading out into the water. Stem creeping, generally 

 naked below, irregularly branched ; branchlets erect, often 

 arched ; leaves imbricated, rather rigid, oval, acute, broad at 

 the base, often slightly flattened so as to be subsecund, 

 serrate; nerve' reaching far above the middle; fruitstalk 

 even ; sporangium firm ovate, cernuous ; lid rostrate, acute, 

 two-thirds as long as the sporangium. 



Schimper describes the leaves as decurrent at the base, but 

 I find them as described by Wilson. It varies much, according 

 to the locality, and sometimes has very concave leaves, which 

 are not at all distichous. 



26. H. murale, Neck.; stem creeping, irregularly branched; 

 branchlets crowded, erect, obtuse ; leaves concave, subelliptic, 

 with a short, abrupt point, entire or finely serrate; nerve 

 reaching above halfway; fruitstalk even; sporangium ovate; 

 lid rostrate. Hook. % Wils. t. xxiv. ; Eng. Bot. t. 1038.; 

 (Plate 6, fig. 2) ; Moug. % Nest. n. 145. 



On rocks and stones, especially those which are calcareous. 

 Not uncommon. Fruiting in winter and early spring. 



Monoicous ; forming pale-green patches, or sometimes 

 tinged with red ; stem creeping, loosely branched, with 

 numerous shining, crowded, cylindrical, often obtuse branch- 

 lets; leaves densely imbricated, or rather distant, concave, 

 elliptic, shortly mucronate, nearly or quite entire; nerve 

 reaching more than halfway up ; fruitstalk even, half an inch 

 high; sporangium ovate, cernuous; lid with along beak. 



The leaves vary, in different forms, in being more or less 

 concave, and having a more or less^ecided point; they are 

 never however acuminate as in the next species. 



27. H. confertum, Dicks.; stem creeping; branches sub- 

 pinnate ; branchlets erect; leaves erecto-patent or complanate, 



