MUSCI. 355 



-f- +- +- Peristome-teeth dividing to the base, the usually filiform divisions mostly equal, wholly 



distinct or more or less coherent in pairs. Capsule oblong or cylindrical, long-pedicellate. 



n- Peristome without basilar membrane : leaves dull and papillose. 



10. Ceratodon. Leaves lanceolate : capsule subcernuous, striate becoming sulcate. Teeth 



cleft nearly to the base, the equal distinct divisions prominently jointed. 



11. Didymodon. Leaves linear or linear-lanceolate. Capsule erect. Teeth short and fuga- 



ceous, entire or cleft to the base into filiform divisions. 



+t ++ Peristome upon a more or less produced basal membrane : capsule erect. 

 = Leaves smooth and shining. 



12. Leptotrichuni. Leaves lanceolate-subulate, not crisped when dry. Teeth equally or un- 



equally cleft to the base, the divisions distinct or coherent. Basal membrane narrow. 

 = = Leaves dull and papillose. 



13. Trichostomum. Leaves linear or lanceolate, mostly acuminate. Teeth often imperfect, 



equally divided, the filiform divisions rarely wholly distinct, erect or slightly twisted. 



14. Desmatodon. Leaves soft, broader ovate- or obovate-oblong, obtuse or obtusish. Teeth as 



in the last, rather short and subulate, incurved when dry. 



15. Barbula. Leaves various. Filiform divisions distinct, mostly very long and twisted. 



* * Leaves opposite, distichous. 



16. Fissidens. Leaves infolded at base, equitant (a dorsal wing produced into a vertical blade). 



Capsule oval or oblong, cernuous. Teeth as in Dicranum, filiform-lanceolate, horizon- 

 tally inflexed when dry. 



17. Distichium. Leaves subulate-setaceous, spreading, shining. Capsule oblong or cylindrical, 



erect or nodding. Teeth subentire or bifid. 



TRIBE III. GRIMMIE^E. Caulescent perennials, with dull leaves in several ranks, the areo- 

 lation minutely round-hexagonal or punctate above, and hexagonal or linear and often 

 sinuous at base. Flowers bud-like. Calyptra mostly mitriform, smooth or sulcate and 

 often hairy. Capsule erect or sometimes nodding, pedicellate, usually regular. Peristome 

 single or double, or sometimes none ; teeth 4, 8 or 16, entire or more or less bifid, usually 

 flattened ; cilia alternate with them when present. 



* Peristome none, 

 j- Leaves nerveless, hyaline at the apex : capsule not striate nor apophysate. 



18. Hedwigia. Capsule globose, immersed. Calyptra mitriform, covering only the convex or 



umbonate operculum. 



19. Braunia. Capsule long- pedicellate, turbinate. Calyptra cucullate, covering the capsule. 



Operculum conic, obtuse. 

 +- +- Leaves costate, not hyaline at the apex : capsule 8-striate, with obconic collum. 



20. Zygodon. Capsule scarcely exserted, ovate, becoming urceolate. Calyptra cucullate, cov- 



ering the obliquely short-beaked operculum. 



* * False peristome of four rigid triquetrous entire teeth . 



21. Tetraphis. Capsule cylindric, long-pedicelled. Calyptra mitriform, naked, irregularly sul- 



cate. Leaves ovate-lanceolate, costate. 



* * * Peristome single, purple or orange, of 16 distinct teeth, entire or more or less deeply cleft, 



often perforated : capsule rarely striate or sulcate. 

 -f- Calyptra not plicate nor hairy. 



22. Grimmia. Low, growing in circular more or less compact tufts. Leaves often setosely 



tipped. Calyptra lobed-mitriform or cucullate, smooth. Operculum obtuse or shortly 

 beaked. Capsule erect or nodding, immersed or shortly exserted. 



23. Rhacomitrium. Taller, cespitose. Leaves often denticulate-acuminate. Calyptra lobed- 



mitriform, rough-beaked. Operculum narrow, mostly aciculate-beaked. Capsule erect, 

 usually long- pedicellate. 



-f- +- Calyptra lobed-mitriform, plicate. 



24. Ptychomitrium. Rather tall, tufted. Leaves linear-lanceolate, denticulate above. Cap- 



sule erect, long-pedicellate, with aciculate operculum. 



* * * * Peristome double or single, or rarely none (in Encalypta), usually pale, of 16 entire 

 teeth, not perforated, often in pairs : capsule mostly striate and at length sulcate, erect : 

 calyptra large, mitriform or campanulate, often hairy. 



25. Orthotrichum. Calyptra campanulate, plicate. Capsule immersed or exserted, apophysate. 



Operculum short-conic. Teeth mostly in pairs, usually reHexed when dry, with often 

 8 or 16 inner cilia. 



26. Encalypta. Calyptra long-cylindric, rostrate, not plicate. Capsule long-pedicelled, with- 



out collum. Operculum long-beaked. Peristome single or none. 



