434 HYPNACEiE. 



inconspicuous. The leaves are usually described as sub-complanate and rarely sub- 

 secund, but in every specimen I have seen, when not distinctly the var. nitidulum, 

 they are markedly homomallous, although with a somewhat distichous insertion ; and 

 any tendency to spread out and become complanate is distinctly exceptional. The 

 variety is very different in habit from the usual form, with the leaves regularly 

 complanate and the branches therefore flattened, prostrate, and not erect nor ascend- 

 ing ; the leaves are perhaps a little larger and more longly acuminate in general, and 

 the colour often of a deeper green, but even these characters are inconstant, and 

 the others frequently given, as to the form and direction of the capsule, the aggrega- 

 tion or otherwise of the male flowers, are quite valueless. 



If attention be paid to the form of the leaf, especially at its base, there will be no 

 difficulty in distinguishing this species from all the allied plants ; in P. latebricola and 

 others the leaves are flrotfe-lanceolate and decurrent, in P. demission distinctly 

 narrowed at the base with very distinct areolation. Hypnum incurvatum differs 

 in the leaves not sub-distichous nor complanate, more narrowly lanceolate with 

 numerous distinct angular cells. 



4. Plagiothecium silesiacum B. & S. (Hypnum silesiacum 



Selig. ; Isopterygium repens Lindb.) (Tab. LV. G.). 



Moderately robust, stem creeping, with irregular branches 

 ^-i inch long, procumbent and often rooting at their tips, 

 frequently attenuated at apex ; forming flat, loose, shining tufts, 

 pale or yellowish green. Branch-leaves spreading when dry, 

 more strongly so when moist, frequently somewhat distichous and 

 complanate at base, almost always secund and curved upwards at 

 the points, especially towards the tips of the branches ; ^ line 

 long or rather more, triangular-lanceolate or oblong-lanceolate, 

 tapering to a long, narrow, almost filiform acumen, at base 

 slightly narrowed, not decurrent and hardly excavate ; margin 

 plane, denticulate, the acumen rather remotely and sharply 

 toothed ; nerve double, short and faint. Cells linear, 10-15 times 

 as long as wide, laxer towards base, a few at extreme base sub- 

 rectangular, but hardly distinct. Seta f-i inch long ; capsule 

 rather large, r line long, cylindric, curved, not striate ; lid 

 conical, obtuse. Peristome teeth densely barred ; cilia well 

 developed. Autoicous. 



Hab. Rotten tree trunks in woods, principally in subalpine districts. Very 

 rare ; Kent ; Yorkshire. Fr. summer. 



Known from P. striatellum by the smooth capsule and the absence of distinct 

 angular cells ; from P. Borreriantwi by the secund leaves curved upwards at the 

 points, with longer, more tapering acumen, and especially by the autoicous 

 inflorescence ; from the last species and P. latebricola by the larger size, larger, 

 toothed leaves, etc. The remaining species have the leaves shortly pointed, not 

 longly acuminate. 



5. Plagiothecium striatellum Lindb. (Leskea striatella 

 Brid. ; Plag. Michlenbeckii B. & S., Schp. Syn., et mult, auct.) 



(Tab. LV. H.). 



Slender, in rather dense low tufts, dark or yellowish green, 



