6 BRITISH HEPATIC^. 



Rootlets white, capillary, rare on the upright stems, but more 

 frequent on the decumbent shoots and flagellse. 



Leaves erect, closely and bifariously imbricated, so as to entirely 

 conceal the stem, ovate, concave, acutely emarginate, the lobes and 

 sinus acute (f. 2), or in some specimens rather obtuse. Margin 

 entire, with a narrow scariose diaphanous border. Surface minutely 

 papillose. 



Texture thin but firm, scarcely altered when dry. Oolour pale 

 glaucous silvery-olive, sometimes with an ochraceous or brown 

 tinge ; when old nearly white. 



Reticulation " guttulate," pellucid near the margin. Cells in 

 the upper third of the leaf hexagonal, with a clear ill-defined out- 

 line ; interior filled with an oval yellowish mass of endochrome, 

 size from xiTo" to xtTo"- Oi^ treating with liquor potassse and 

 the iodine reagent, thejundefined broad border is replaced by a 

 delicate double contour, and the interior occupied by a violet- 

 coloured six-sided figure, the contracted ' membrana secundaria.' 

 Near the base and central part of the leaf the cells are oval or 

 oblong, ttVs" to 5^" long, by tt^" broad. 



Dioicous. Fertile shoots more tumid, and clavate. Involucral 

 leaves, 3 to 4 pairs, larger than the ordinary ones, their margin 

 more or less reflexed ; upper pair broadly ovate, connivent, hi- or 

 tri-dentate at the apex ; sometimes with a third entire or bifid lobe 

 (amphigastrium), (f. 7) ; margin irregularly recurved-denticulate. 

 On removing the outer leaves, the organs of fructification are found 

 to be closely surrounded" by an inner involucre (f. 5), composed of 

 2 or 3 smaller leaves, of thinner texture and more open reticulation. 

 These are inserted into the thickened base of the calyptra, and 

 adnate for a short distance with each other. The two anterior 

 leaves are larger, convolute, more or less deeply cleft into six or 

 eight irregularly-dentate segments (f. 2). The posterior leaflet 

 (amphigastrium) is not always distinguishable ; ovate, either entire 

 or lobate denticulate. 



Calyptra campanulate, thickened at the base, where it unites 

 with the cellular tissue of the receptacle to supply a pouch for the 

 growing capsule, barren pistillidia, 6 or 8 in number, scattered 

 over the lower half of the calyptra. 



Capsule rather small (f. 2, 8), spherical, chocolate-brown, 

 polished; valves four (f. 5), ovate, annulate-punctate, recurved 

 when empty. 



Peduncle two to four lines in length, white, succulent. 



Spores dark fulvous, sphseroidal, xrso" i°- diameter. 



Maters bi-spiral, length g^" to -g^e ", breadth ^q^oo "- 



Male shoots more slender, fastigiate. 



Perigonial leaves (f. 4) obliquely amplexicaul, sub-secund, ven- 

 tricose at the base, complicate-concave, bi-lobed, the lobes acute, 

 connivent, dorsal margin reflexed. 



