250 ORTHOTRICHACEiE. 



dark brown, moderately hairy. Peristome teeth 16, or in 8 pairs, 

 erect when dry, marked with faint sinuose lines, with two small 

 lamellae standing before each tooth, and reaching about as high 

 as the 2nd or 3rd articulation ; processes absent or rudimentary. 

 Autoicous. 



Var. /8. saxatile Milde (var. cylindricum Schp., Braithw. Br. 

 M. Fl. ; Schp. Syn.). Capsule narrower, narrowly cylindrical, 

 8-striate, usually on a longer seta; peristome teeth in 8 pairs, 

 hardly divided, processes usually more or less well developed. 

 Leaves narrower, rather more acute. 



Hab. Rocks ; the type usually on siliceous, the var. j8 almost always on 

 calcareous ones. The type rare ; the var. frequent. Fr. early summer. 



Although the plant here described as var. saxatile is a somewhat constant form, 

 and quite different in its habitat and distribution from the type, yet the differences 

 are really slight, and the characters derived from the leaves are perhaps hardly reliable. 

 Rarely, too, a single capsule will show distinct traces of intermediate bands or striae, 

 It appears to be common throughout the calcareous districts of Mid-England, where 

 O. anomalum proper is quite absent. 



0. anomalum differs from 0. cupzilatum in the longer seta and in the form of 

 the capsule, which in that is shorter and wider, more suddenly tapering, and hardly 

 exserted above the perichsetial bracts ; in the var. saxatile of the present species the 

 seta is sometimes longer than the capsule and neck together. From 0. rupestre our 

 plant differs notably in the immersed stomata and the 16-striate, more exserted capsule. 



3. Orthotrichum cupulatum Hoffm. (Tab. XXXV. A.). 



Resembling the last, and indeed hardly separable except by 

 the fruit ; tufts more often rather loose, leaves oblong-lanceolate 

 or oval-lanceolate, obtuse or sub-acute, margins revolute ; cells as 

 in the last, in one layer. Capsule immersed or emergent, rarely 

 almost exserted, widely oval, quickly narrowed at base to a very 

 short seta ; when dry widely and shortly cylindrical, brownish 

 green ; when old and empty urceolate, contracted below the 

 reddish brown mouth, wider and pale below ; ribs usually 16, 

 8 long and of 2-3 cells in width, reaching nearly to base of the 

 capsule, 8 intermediate, shorter and fainter, rarely almost or quite 

 obsolete. Stomata immersed, very little hidden. Calyptra widely 

 campanulate, very sparsely hairy, brown or yellowish. Peristome 

 simple, rarely with rudimentary processes ; outer teeth spreading, 

 resembling those of the last species, but almost equidistant. 

 Autoicous. 



Var. (i. nudum Braithw. (O. cupulatum var. riparium Schp., 

 Syn.). Tufts wider, looser, dark green. Capsule on a longer 

 seta, almost exserted, with a longer, more tapering neck ; calyptra 



