GRIMMIA. 137 



8- Grimmia pulvinata Smith. (Bryum pulvinatum L.) 



(Tab. XXI. L.). 



In small, rounded, neat, dense cushions, J-i inch high, hoary 

 with the hair-points of the leaves. Upper leaves broadly oblong- 

 lanceolate, wide at apex, about f line long, spreading, when dry 

 erect and oppressed, ending in a long flexuose denticulate hair, 

 the lower narrower ; margin slightly recurved below, thickened 

 above ; nerve distinct ; cells all short, at base lax and shortly 

 rectangular, hardly any as much as twice as long as wide, 

 almost uniform throughout the breadth of the leaf, thin-walled; 

 gradually becoming shorter and smaller above and incrassate, 

 quadrate-hexagonal and rounded, with the walls sinuosely 

 incrassate. Seta cygneous, reddish, capsule hidden among the 

 comal leaves — after maturity the seta, when dry, becomes erect — 

 calyptra mitriform (rarely sub-cucullate) ; capsule oval, when dry 

 reddish brown, wide-mouthed, widely but distinctly 8-striate ; lid 

 shortly rostellate, straight or oblique ; peristome teeth dull red, 

 spreading when dry, densely barred, unequally divided above and 

 perforated. Annulus broad. Autoicous. 



Var. /S. obtusa Hiibn. (Dryptodon obtusus Brid.). Capsule 

 smaller, on a shorter seta, shorter, the lid obtuse, shortly and 

 bluntly pointed. 



Hab. Walls and rocks in lowland districts. Common. The var. /3 rare. Fr. 

 spring. 



This is the commonest species of the genus, and may usually be found on almost 

 any stone wall loaded with capsules in one stage or another of development. It is 

 very rarely found at high altitudes. The neat, round, hoary cushions, the cygneous 

 fruitstalks and the comparatively broad leaves will easily distinguish it from all species 

 but the next, to which indeed, as far as concerns the fruit, the var. obtusa is .in some 

 degree an approach. The broader leaves with uniformly short basal areolation will 

 separate it from that without difficulty under the microscope. 



9. Grimmia orbicularis Bruch. (Tab. XXII. A.). 



Resembling the last species. Cushions larger and less 

 defined, stems more readily separating when gathered. Leaves 

 narrower, oblong-lanceolate, rounded at apex ; margin not 

 thickened; cells near the nerve linear-rectangular, 6-8 times as 

 long as broad, yellowish, the others as in the last, at angles 

 shorter, wider, hyaline in two or three marginal rows ; the upper 

 cells resembling G. pulvinata. Seta pale; calyptra cucullate ; 

 capsule smaller, oval-globose, when dry very faintly striate, 



