BRITISH HEPATICiE. 5 



The Gymnomitria are readily distingviislied by the rigid julaceous tMcHy-matited 

 ■'.oots, resembling (as Lightfoot. well remarks), under the microscope, the texture of a 

 braided lock of hair, or the plaited thong of a whip. The colour, too, is characteristic, 

 silvery-olive, or cream-white, rarely darker gray, or smoky-brown. 



1. Gymnomituium concinnatum, Corda. 



Plate I. Fig. 2. 



Barren shoots erect, simple or fasciculately branched, slightly- 

 compressed, thicker and obtuse at the apex; leaves imbricated, ovate, 

 bidentate, sinus and lobes acute, border narrow, membranous. Eer- 

 tile shoots clavate ; involucral leaves larger, vrith reflexed margins, 

 upper ones connivent, irregularly dentate-lobate. 



Jungermannia concinnata, Lightf. Fl. Scot. ii. p. 786 ; Eng. Bot. t. 2229, ed. 2, 

 1820; Hook. Jung. p. 11, t. iii. ; Fl. Danica, t. 1002 ; Muse. Brit. ed. 2, p. 229 ; 

 Br. Fl. V. i. p. 110. 



Gymnomitrium concinnatum, Corda, in Sturm. Fl. Germ. Or. xix. xx. p. 23, t. 4 ; 

 N. ab E. Eur. Leberm. i. p. 115 {et seq.) ; Gottsche & Eab. Hep. Eur. Ex. n. 423 

 (c. icon.) ; Syn. Hepat. p. 3, n. 1. 



Acolea concinnata, Dnm. Syll. p. 76, n. 108, t. 2, f. 15 ; Eecueil d'Obs. Jung. p. 23. 



Jung, gymnomitrioides, N. ab E. 1. c. ii. p. 52. 



Hab. Frequent in barren spongy places near the summits of most of the moun- 

 tains of Scotland. More rare in England, and confined to the sub-alpine northern 

 districts : — Helvellyn, Nowell, 1857 ! Oronkley Scar, Teesdale, J. G. Baker I Snowdon, 

 G. E. Hunt 1 Glyder, W. Wilson ! Cader Idris, Mr. Ralfs. Irish localities refer to 

 G. crenulatum. Fbuit, Summer. Found on primary rocks in Northern and Central 

 Europe, 



Fronds growing in thickly matted tufts, sometimes a foot or 

 more in diameter, "conspicuous at a considerable distance from 

 its silvery hue." 



Frimary shoots creeping, flageUiferous, at length ascending, 

 radiculose on the underside, half an inch or more in length, 

 simple, or bearing a few suberect branches, which are thinner a-nd 

 cylindrical below, but compressed and incrassated near the apex 

 (f. 2). Prom the upper part of the old shoots innovations are fre- 

 quently produced, which are at first slender, but at length attain 

 the ordinary form. Sometimes the stems assume a remarkable 

 interrupted appearance from repeated proliflcation. Flagellos 

 creeping, densely matted together, rigid, filiform, of a brownish 

 colour ; either naked or squamose at the extremity, at length 

 ascending, and producing true leaves. 



Prom the densely csespjtose habit of the older patches, the ori- 

 ginal ramification is imperfectly seen, since the rhizomatous shoots 

 and lower portions of the stem soon decay, and crumble away, 

 leaving only the upper even-topped stratum visible and intact. 



