382 LESKEACE^E. 



imbricated, widely oval, with a short point or a longer, tapering 

 acumen, acute, strongly plicate, margin slightly recurved, denti- 

 culate above; nerve strong, reaching § the length of the leaf or 

 higher ; cells minute, oval, incrassate, at mid-base very slightly 

 elongated, towards basal margins shorter, subquadrate-rounded, 

 all highly papillose at back. Paraphyllia numerous, short, 

 multifid, often united with the leaf at base. Branch-leaves much 

 smaller, crowded, ovate, shortly acuminate, concave, when dry 

 closely imbricated , so that the branches are terete, areolation 

 minute, oval, or irregularly rounded, highly papillose, especially 

 at back ; the apical usually bifid, rarely simply acute ; nerve 

 hispidly papillose at back. Perichaetial bracts long, gradually 

 attenuated, plicate, without cilia. Capsule suberect, curved, 

 cylindrical, slender ; lid conical, acuminate. Dioicous. 



Hab. Among grasses, etc., principally on dry calcareous soil ; frequent. Fruit 

 extremely rare, not found in Britain. 



T. abietinum varies in slenderness and in the form of the stem-leaves, but not to 

 any great extent in other directions. It is readily distinguished from T. Blandcrvii 

 and T. decipiens by the habitat, the closely imbricated branch-leaves, the areolation, 

 the more rigid texture of the stem and leaves, the darker colour, etc., and from the 

 former notably by the dioicous inflorescence ; from all the other species by the colour, 

 the simply pinnate stems, and narrow, less cordate stem-leaves. 



This and the next two species belong to Mitten's sub-genus Tetracladium, 

 distinguished by having the branches not complanate, but in four rows, two on each 

 side of the stem, the upper on one side and the lower on the other being in the same 

 plane. This is noticeable in fresh plants and specimens which have not been 

 subjected to pressure ; in herbarium specimens which have been pressed flat it is of 

 course indistinguishable, but may be recovered more or less by immersion in water. 



2. Thuidium Blandovii B. & S. (Hypnum BlandoviiW. & M.) 



(Tab. LI. A.). 



Somewhat resembling the last species, but of paler colour 

 and softer texture ; bright or yellowish green above, pale below; 

 stems not rigid, leaves soft, thin and somewhat membranaceous 

 in texture. Stems and leaf-bases thickly coated with numerous 

 long and branched, filiform, pellucid, jointed paraphyllia ; stem- 

 leaves wide, cordate-acuminate , often much narrowed at the base, 

 thin and pellucid, irregularly plicate, densely crowded, so as to 

 render the stems tumid; margin slightly recurved, or plane, 

 towards base spinulosely-papillose ; nerve thin, reaching above 

 half-way ; cells narrowly vermicular-elliptical , or linear-rhom- 

 boid, 4-6 times as long as broad, longer and more vermicular at 

 apex, longer and narrowly rectangular at base ; at back with 

 strong but not very dense papillae, usually arising from the end- 

 walls, not from the face of the cells. Branches slender, 



