FISSIDENS. 125 



forms may with certainty be looked for in the variable F. crassipes. Fruiting specimens 

 gathered by the Rev. H. G. Jameson in the R. Wharfe (from which the above 

 description of the fruit is taken) do not agree with the descriptions of either Braith- 

 waite or Boulay ; they have the cells however less incrassate than usual, and possibly 

 are not typical F. rufulus, but they certainly cannot be referred to the last or to any 

 other of our species. 



10. Fissidens osmundoides Hedw. (Dicranum osmundoides 



Sw.) (Tab. XX. K.). 



Tall, in dense tufts, very compact at the base, 2-6 inches 

 high, bright or yellowish green ; stems slender, branched, 

 radiculose. Leaves short, broadly lingulate, abruptly narrowed at 

 apex and apiculate, or broadly pointed; sheathing laminae more 

 than half the length of the leaf, broad; inferior lamina reaching 

 nearly to the base of the leaf, often abruptly ceasing ; areolation 

 larger than in any of the foregoing species, 14-20 /* wide (but often 

 much smaller even in leaves from the same stem), more regularly 

 hexagonal-rounded, incrassate , a single row at margin smaller and 

 often paler or discoloured, but without a thickened border of narrow 

 cells ; a row or two on each side of the nerve also often paler and 

 more pellucid ; nerve ceasing some distance below the apex ; margin 

 faintly and regularly crenulate with the projecting cells, which 

 are also turgid and prominent at the back of the leaf. Seta 

 terminal, purple ; capsule rather small, narrow-oblong, erect or 

 slightly inclined, thick-walled, dark coloured ; calyptra mitriform, 

 lobed at the base, or cucullate ; lid long, rostrate. Dioicous ; male 

 flower terminal. 



Hab. Wet rocks and mountain slopes. Not common. Fr. summer. 



Quite distinct from any of the other terminal-fruited species in the tall, slender 

 growth and non-bordered leaves. It is more likely, in the absence of fruit, to be 

 confused with one of the following species, especially F. taxifolius and F. decipiens, 

 the latter of which it much resembles in habit ; the former will be easily known by 

 its shorter stems and narrower leaves with the nerve percurrent or even excurrent ; 

 and F. decipiens by its longer, serrated leaves with broad margin of paler cells, and 

 much smaller areolation. 



The cells in this species vary considerably in size, even on the same stem, but 

 ordinarily they are of about the dimensions given above, or even larger in the lower 

 leaves of the stem ; the smaller cells appear indeed to be confined to the upper leaves. 



11. Fissidens serrulatus Brid. (Tab. XX. L.). 



Loosely tufted, pale green, robust ; stems simple or branched 

 at the base, 1-3 inches high, erect. Leaves very large, crowded, 

 longer towards the top of the stem, broadly lingulate, sometimes 

 \ inch in length, straight, solid; at apex shortly acuminate or 

 acute, the tip often irregular and turned to one side, unequally 



