HYPNUM. 477 



texture, denticulate margin, etc., of the leaves of that plant, and its general habit, are 

 widely different. 



H. Bambergeri, when, as occasionally happens, it is somewhat regularly pinnate, 

 much resembles H. procerrimum, and specimens of this habit, which I gathered on 

 Ben Lawers in 1893, were indeed so named by Boswell ; that species however differs 

 in the much more regularly pinnate stems, and in the large leaves, dilated at the base, 

 with the areolation, including that at the angles, thin-walled, not incrassate, and the 

 angular cells numerous. 



H. cupressiforme differs in the less circinate leaves with thin-walled areolation, 

 and opaque, not coloured, angular cells, and other points. 



23. Hypnum procerrimum Mol. (Tab. LVIII. L.). 



Robust, closely and regularly pinnate, resembling the most 

 plumose forms of H. molluscum ; stems not radiculose, slightly- 

 divided, 2-4 inches long, olive green or yellowish brown. Leaves 

 regularly falcato-secund, large, ij-if lines long (branch-leaves 

 much narrower, smaller, more circinate), widely ovate-oblong 

 from a broad, somewhat dilated, excavate and auriculate base, 

 gradually narrowed to a long, tapering acumen, plane at margin 

 and quite entire or sinuolate only, usually very slightly rugose or 

 crisped when dry ; nerve very short and faint, double ; cells 

 rather short, 8-12 times as long as broad, linear-flexuose, 

 tapering, but not acute, thin-walled, at basal angles laxer and 

 shorter, the lowest numerous, quadrate or hexagonal-quadrate, 

 small, opaque, or more rarely pellucid, slightly incrassate, 

 forming large, distinct, but not clearly defined, rounded, often 

 orange auricles. Dioicous. Fruit unknown. 



Hab. Alpine calcareous rocks, very rare. Ben Lawers (Meldrum, 1891). 



A very fine species, distinguished from its allies by the regularly pinnate, plumose 

 stems and large leaves ; from H. cupressiforme by the distinct, expanded, auricular 

 leaf-base with very numerous angular cells, etc. ; from H. molluscum, which perhaps 

 it most resembles, by the quite entire leaves of closer, firmer texture. 



In the specimens from Ben Lawers, which Mr. R. H. Meldrum has kindly sent 

 me, the branching is a little more irregularly and interruptedly pinnate than in 

 continental specimens, and the stem-leaves a shade smaller and less expanded at 

 the base, so that if has not quite so distinctive a habit for field recognition ; but in the 

 leaf structure it is quite typical ; and as far as my observations go it may be 

 distinguished in the dry state by the leaf points always more regularly falcate, less 

 twisted and undulate than in H. molluscum, which in its more robust forms, also, has 

 the leaves distinctly striate. 



24. Hypnum canariense Mitt. (Tab. LVIII. H.). 



Closely resembling H. cupressiforme except in the fruit. 

 Stems slender, prostrate, densely pinnate; leaves crowded, 

 strongly falcato-secund, ovate-lanceolate or oblong-lanceolate, 

 gradually tapering to a long, narrow, flat acumen ; margin 

 sharply denticulate, especially above ; nerve faint and double or 



