DICRANOWEISIA. 89 



pellucid, with distinct hyaline or coloured inflated angular cells. 

 Perichaetial bracts more distinct, pale, sheathing. Capsule on a 

 longer seta (|-| inch), oval-elliptical, shorter and wider, broadest 

 near the base, with a wider mouth, faintly plicate-rugose when 

 dry, exannulate. Peristome teeth inserted below the mouth. 

 Autoicous. 



Hab. Mountain rocks ; not common. Fr. early summer. 



On high mountains this species becomes almost black ; and at great heights, 

 when exposed to dripping water, it becomes dwarfed, with shorter leaves and capsules 

 (var. atrata N. & H.). D. compacta (Schleich.), which appears to be properly 

 regarded as a variety of this species, has been recorded from Ben Lawers, but incor- 

 rectly, according to Braithwaitei It has shorter, more obtuse leaves, hardly crisped 

 when dry. 



D. crispula will easily be distinguished from D. cirrata by the characters 

 italicised above. Grimmia contorta closely resembles it when growing, but the 

 present plant is usually taller, a little more glossy in its leaves, which are often 

 secund above when moist, rather more twisted and curled when dry, and, of course, 

 entirely wanting in the hyaline tip to the leaves. Still plants may be found which 

 defy recognition until placed under the microscope, when, of course, their identifica- 

 tion is easy. 



24. OAMPYLOPUS Brid. 



Mosses of varying size, often robust, usually growing in wide 

 patches, resembling Dicranum in habit, but with the leaves more 

 rigid, less flexuose, and generally straight; not papillose; 

 nerve mostly very broad, often longitudinally furrowed at back, 

 usually with one or more layers of larger, hyaline, thin-walled 

 cells on the anterior or ventral surface. Angular cells often 

 forming distinct concave auricles. Calyptra cucullate, generally 

 fringed at base. Seta flexuose, usually cygneous, rarely erect 

 (becoming erect when dry and mature) ; capsule small, elliptic, 

 symmetrical , usually striate ; peristome dicranoid. 



All the British species are dioicous, and the fruit in most 

 cases is extremely rare ; hence their determination must rest 

 mainly on vegetative characters. The width of the nerve and its 

 structure for the most part furnish important distinctions, as does 

 also the basal areolation ; the cells in the upper part of the leaf, 

 however, are too uniform to be of much aid, except in one or two 

 cases. These islands are particularly rich in species of this 

 genus, more so than any continental country ; indeed, all the 

 European species are found in Britain, while two of our species 

 are endemic. In several of the species the leaves are extremely 

 fragile and deciduous, and, being capable of producing out- 



