Dicranum.} MUSCI. 21 



16. Glyphomitrion, Bride/. 



Seta terminal. Peristome single, of 16 teeth approached in 

 pairs, reflexed when dry. Calyptra covering the entire mature 

 capsule, campanulate, split at the base, furrowed. 



1. G. Daviesii, Bridel. Stems fastigiate ; leaves lineari- 

 lanceolate, their margins recurved, concave ; capsule turbinate. 

 Brid. Mant. Muse. p. 31. Muse. Brit. ed. 2, t. 13. 



On rocks at Fairhead, County of Antrim, near Bantry, Miss Hutchins. 

 In both instances accompanied by Trick, ellipticum. 



2. G. cylindraceum. Stems fastigiate ; leaves ovato -lanceo- 

 late, carinate, their margins recurved; capsule ovato-cylindra- 

 ceous. 



In the crevices of siliceous sandstone rocks on Blackwater Hill, 

 County of Kerry. Stems | an inch high, branching in a fastigiate 

 manner. Leaves incurved and crisped when dry, crowded towards the 

 summit of the branch, very dark green below, of a livelier green on the 

 top, comprising the growth of the preceding season ; from a broad or 

 ovate base lanceolate upwards, concave, carinate, the nerve percurrent, 

 thick, the margins recurved. It has a distinct perichcetium much 

 shorter than in the preceding, measuring half the length of the pedicell, 

 Capsule cylindraceous, wider at the base. Lid from a convex base 

 elongato-rostrate inclined. Calyptra covering the mature capsule, cam- 

 panulate furrowed, split below into 4 or 5 lacinice. Teeth of the peris- 

 tome 16, approached in pairs, lanceolate, red, transversely barred. The 

 perichcetium usually appears lateral. 



17. Dicranum. Hedw. 



Seta terminal. Peristome single, of 16 bifid, equidistant teeth; 

 Calyptra dimidiate. 



D. adiantoides and D. taxifolium have the setce lateral : these 

 belong to the very natural genus Fissidens of Hedw., which to 

 the shame of our artificial methods we know not how to sepa- 

 rate from Dicranum. 



A. Leaves bifarious. (Fissidens, Hedw.) 



1. D. bryoides. Swartz. Seta terminal; perichcetial leaves si- 

 milar to the cauline. Swartz. Muse. Saec. t. 2, f. 4. Muse. Brit, 

 ed. 2, p. 88, t. 16. 



On moist banks : common. This species varies by the length of the 

 stem, by its sometimes remaining simple, and by the erect or inclined 

 position of the capsule. It has long been observed, that in all the plants 

 of this section of the Genus Dicranum, there is a duplicature of the 

 pagina of the leaf proceeding from the inferior half of the nerve 

 towards the margin next the stem. Such a structure is remarkable 

 among the Musci. I have witnessed it only in another Genus from 

 Nepal, whose capsules, however, are sessile, axillary, in structure like 

 those of a Phascum. 



