18 



BRITISH HEPATICiE. 



Stems creeping (f. 6, 2), and intricately matted together at the 

 base, which, is naked or beset only with the ramenta of old leaves, 

 ascending or erect, rather thick for the size of the plant, rigid, 

 subligneoiis, at first simple, but producing innovations from the 

 terminal axis of the shoots, or from the axillse of leaves ; 2 to 6 

 lines long, of a brown or nearly black colour. Shoots (f. 6, 3, 8) 

 slightly compressed, catenulate when dry, pectinate-pinnate when 

 moist, sub-clavate at the apex, or in barren innovations attenuate. 



Rootlets confined to the creeping portion of the stem and 

 stolons. 



Xieaves scarcely wider than the stem, of nearly uniform size, 

 somewhat smaller and more distantly placed near its base, and on 

 innovant shoots, whilst they are more crowded at the apex ; round 

 or sub-quadrate (f. 6, 4), sometimes roundish-ovate, acutely emar- 

 ginate ; sinus equal to a third or fourth of the length ; lobes equal, 

 acute or a little obtuse, divergent. The leaves are of nearly uni- 

 form size, laxly and sub-vertically imbricated, semi-amplexicaul, 

 very concave, inflexed (but not vaginate) at the base. 



Texture firm and compact, scarcely altered when dry. Colour 

 olive-brown, lurid- brown, or rarely a paler olive ; the leaves are 

 smooth, but scarcely polished, except in var. diffusa. 



Areolation minute, obscurely punctate, the cell-walls thick, 

 appearing crenate from the projecting ' trigones ; ' but after the 

 application of re-agents the true roundish-hexagonal form is deve- 

 loped ; marginal cells sub-quadrate, but not differing perceptibly 

 in size from those of the upper third, xt^' to g^" by ttVo"- The 

 wall is thickened at the angles which unite with neighbouring cells, 

 but the trigones are smaller than in allied species. Basal cells yg^" 

 long by T^To "• The interior is filled with brownish endochrome, 

 and often contains 2 or 3 chlorophyll bodies (zellenblaschen), resem- 

 bling those noted under N. scalaris. 



I>ioicous. Fertile shoots (f. 6, 2) inuch thickened upwards, 

 abbreviate (2-3 lines) ; involucral leaves two or three pairs, sud- 

 denly and remarkably enlarged, broadly ovate, the lobes rather 

 obtuse, sinus acute. 



Involucre conspicuous, ovate, formed of two convolute leaves, 

 connate for half their length ; lobes acute, at first connivent, but 

 after the egress of the capsule erect. 



Oolesule adnate with and hidden by the outer involucral bracts 

 and connective tissue of the dilated stem, only the apex remaining 

 free, which is at first entire, but afterwards split into irregular lobes 

 (f. 6, 6). Its texture is more laxly cellular than the outer portion. 



Calyptra obovate, hyaline, cells rhomboidal, bearing at its base 

 the abortive pistillidia. 



Capsule very minute, round or oval, pale reddish-brown ; valves 

 ovate, thick-walled ; pedicel about 2 lines long, rather thick, suc- 

 culent. 



