34 6 BRYACE^. 



erect, the leaves sub-equal, crowded, not forming a comal rosette, 

 resembling those already described. Margin of leaves with a 

 strong reddish border, spinosely serrate from below the middle 

 with a double row of teeth which are consequently in pairs, each 

 formed of a single spiniform acute cell ; nerve ceasing below the 

 apex, spinose at back above ; cells incrassate, angular, sub- 

 quadrate-hexagonal or irregular, not seriate, rather small, about 

 20 /J. in diameter, the basal rectangular, elongate. Seta solitary, 

 long, i-i£ inches, reddish, cygneous above, capsule sub-pendulous, 

 finally horizontal, rather large, ovate-elliptic with a very narrow 

 but distinct tapering neck, when empty somewhat ventricose, pale 

 yellow with a narrow red rim; lid conical, apiculate ; peristome 

 yellowish. Dioicous ; male flower large, discoid. 



Hab. Sandy banks in woods, and about the roots of trees, sometimes on rocks 

 by streams ; common. Fr. spring. 



A fine species usually known by its dense, robust habit, with the leaves closely 

 set and hardly crisped when dry. It does not vary much, but a very slender form 

 occurs, which I have found on shady sandstone rocks, quite as slender as M. serratum 

 and much resembling that species. M. hornum has something of the habit of M. 

 stellare, but is usually of stronger growth, and its bordered leaves are quite distinct, 

 even with the lens. The species with which it is really likely to be confused are the 

 allied species following ; in its ordinary form and habitat the resemblance disappears, 

 but on wet rocks by mountain streams it may easily be confused with both M. serratum 

 and M. orthorrhynchum. When in fruit the pale capsule and short lid at once 

 designate it ; but these species, especially the latter, are often barren, and it is then 

 sometimes almost impossible to separate them in the field. There is however usually a 

 decided reddish tinge about M. serratum and M. orthorrhynchum, especially in the 

 stems ; the leaves are less crowded, wider, more ovate, and more strongly decurrent ; 

 still lax-leaved forms of M. hornum may defy determination with the lens. Under 

 the microscope the scarcely decurrent leaves will generally distinguish it ; M. serratum 

 also has the cells rounded internally, and in M. orthorrhynchum they are rather 

 smaller. 



6. Mnium serratum Schrad. (M. marginatum P. Beauv., 

 Braithw. Br. M. Fl.) (Tab. XLVII. A.). 



Resembling M. hornum, but more slender, of a darker green, 

 almost always with a deep vinous red tinge in the lower part and 

 with red stems ; leaves shorter, wider, more distant, more con- 

 torted when dry, but hardly crisped ; lower stem-leaves ovate or 

 obovate, upper longer, oblong-spathulate ; all acute and apiculate, 

 narrowed at the base and strongly decurrent ; leaves of the 

 sterile shoots more distant, shorter ; all with a strong red border, 

 doubly spinose-serrate, the teeth acute, obtuse, or sometimes 

 almost obsolete, less crowded than in M. hornum ; nerve red, 

 vanishing below apex, not spinose at back ; cells 20-25 A* ?tt 

 diameter, irregularly rounded, not angular, slightly incrassate, 



