FISSIDENS. 127 



thickened border, usually crowded, broadly oblong-lanceolate, acute 

 or shortly acuminate, crisped when dry, especially at the tip, 

 inferior lamina broad and usually ceasing abruptly at base ; margin 

 crenulate, towards apex more distinctly and unequally serrate ; 

 nerve vanishing at apex. Cells rather large, 12-18 //. wide, 2-4 

 rows at edges often a little paler, forming an obscure marginal 

 band, which is however variable and not always present, most 

 distinct in the older leaves. Autoicous ; fruit lateral, from the 

 middle of the stem, several arising from the same stem ; seta stout, 

 red, flexuose, long ; capsule horizontal and arcuate, or erect and 

 symmetrical, dark-coloured ; lid long-beaked. Male flowers 

 axillary, small. 



IIab. Bogs, wet rocks on mountains, etc. Common. Fr. winter. 



Very variable, but readily recognised at sight by its larger size, etc. , from all but 

 F. decipiens ; fromthis it is known by the larger cells and less distinct marginal band, 

 from F. osmundoides and F. taxifolius by the larger, more serrate leaves, and from 

 the latter species also by the shorter nerve. 



The fruit when it occurs is usually produced in abundance. 



F. collinus Mitt, appears to be only a dwarf form found among grass on the 

 chalk downs of the south coast ; according to Braithwaite there is no difference 

 in the size of the cells between this and F. adiantoides, but it is described by Mitten 

 as with smaller cells than the present species. 



14. Fissidens decipiens De Not. (Tab. XXI. B.). 



Intermediate in size between F. adiantoides and F. taxifolius, 

 usually more slender than the first and taller than the last, but 

 variable ; in dense dull green or blackish erect tufts. Leaves crowded, 

 Ungulate, acute but not acuminate, crenulate at margin, in the 

 upper half unequally serrate ; cells smaller, 6-8 n, more obscure 

 than in F. adiantoides, incrassate ; about four rows at margin 

 more incrassate and less obscure, forming a more distinct pale or 

 yellowish band round the leaf. Dioicous or autoicous ; female 

 flowers often very numerous, seta from middle and lower part of 

 stem, short, slender, pale red ; capsules oval-oblong ; lid rostrate. 



Var. f3. brevifolius Lindb. Leaves crowded, much shorter, 

 less distinctly serrate, with a narrower band of pale cells. 



Hab. Wet rocks in mountainous countries ; rarely among grass at lower levels. 

 Frequent. The var. B, Killarney. Fr. winter and spring. 



The distinctly smaller areolation and the more conspicuous band of marginal 

 paler cells chiefly, and in general easily, characterise this species. It is usually but 

 not always distinguishable from F. adiantoides by the more slender stems, from F. 

 taxifolius by the taller stems and different habitat, and from F. osmundoides by the 

 serrate apex of the leaf and small cells. 



