126 FISSIDENTACE^E. 



serrate ; nerve rather thick, vanishing at apex; cells rather large, 

 10-15 H-i incrassate, often in two strata ; highly papillose with broad 

 conical protuberances, hexagonal-rounded, at margin with about 

 four rows of thinner , paler or yellowish cells, less chlorophyllose 

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

 band to the leaf, regularly crenulate ; inferior lamina wide and 

 ceasing abruptly at base. Dioicous ; male flowers axillary or 

 terminal, large, conspicuous ; fruit terminal, seta stout, yellowish, 

 flexuose ; capsule inclined, oblong, dark brown, thick- walled. 



Hab. Damp banks by streams, and rocks. Very rare ; near Penzance. 



The male plant alone has been found in this country. It is a very rare European 

 species, but grows and fruits abundantly in Teneriffe. From its large size it can only 

 be confused with the following species, or with very robust forms of F. adiantoides ; 

 the latter however never equals it in the length of the leaves, and the cells are larger 

 and much less papillose. F. polyphyllus differs in the characters detailed under that 

 species, of which this is by some writers considered a variety. 



12. Fissidens polyphyllus Wils. (Tab. XX. M.). 



Very robust and tall, 3-12 inches long, deep green, rigid, 

 stems often prostrate or pendent, radiculose. Leaves crowded, 

 sometimes slightly falcate, incurved and flexuose when dry, 

 narrowly Ungulate-lanceolate, very long, without any distinct 

 band of marginal cells, obtusely pointed, minutely crenulate all 

 round, or with a few obscure serratures at point; nerve thick, 

 rather broad ; inferior lamina more narrowed at base, less abruptly 

 ceasing ; cells as in F. serrulatus but smooth or only faintly pro- 

 tuberant. Dioicous ; male inflorescence as in the last ; fruit 

 lateral, near the top of the stem ; capsule as in F. serrulatus. 



Hab. Wet rocks. Very rare. Cornwall ; Devon ; N. Wales ; Ireland. Fruit 

 not found in Britain. 



A still finer plant than the last ; it has only recently been found in fruit, in 

 Finisterre. The narrower leaves without the pale marginal band, and with almost 

 entire less acuminate apex, and the hardly papillose cells, separate it from the last, as 

 do also the habit and colour ; these characters with the different position of the female 

 flower appear amply sufficient to warrant its retention as a species. I have found the 

 nerve in F. 'polyphyllus constantly broader and less well-defined than in F. serrulatus. 



13. Fissidens adiantoides Hedw. (Hypnum adiantoides L.) 

 (Tab. XXI. A.). 



Deep or yellowish green, 1-4 inches high, variable in size and 

 habit, sometimes slender and short-leaved as in F. osmundoides, 

 sometimes robust and rivalling F. polyphyllus. Leaves without a 



