ON TW(i NEAV BRITISH HI-PATIC^. 67 



obliquely orbicular to reniform, entire or very rarely truncate, and 

 bearing one or two teeth at the apex ; convex margin inflexed, poste- 

 rior lobe abruptly rounded, the anterior very narrow and decurrent. 

 Colour pale olive or stramineous ; texture firm, polished, scarcely altered 

 when dry. Areolation " dotted," that is to say, the true outlines of 

 the cells are obscured, and what is in truth the cell-cavity is mistaken 

 for the cell. If, however, a leaf be boiled in Liquor Potassfe, and a 

 few drops of Iodide of Zinc solution added, the true outbnes will 

 appear as a clear narrow band surrounding the six-sided cells. Each 

 angle of the cell is seen to be occupied by a triangular body, the 

 " trigonura interstitiale " of authors, which is a deposit of cellulose 

 within, not outside the cell, and, like the outer walls, uncoloured by 

 the Iodide of Zinc ; whereas the six-lobed " membrana secundaria," 

 enclosing the processes (pori) of the primordial utricle of Mohl is 

 coloured violet by the solution. The cell-structure alone will serve 

 to distinguish A. Carringtoni from Nardia compressa, in which the 

 limits of the cell are well marked without preparation, and the trigones 

 are absent or inconspicuous. The leaves, too, in that species are 

 nearly plane, appressed to each other, and gradually enlarging to the 

 apex of the stem ; their texture is more tender and delicate, the colour 

 a pale, translucent green, often tinged with purple, and they project 

 equally on each side of the stem, and, from their succulent texture, 

 they shrink more when diy. The immersed terminal involucre, when' 

 present, will at once distinguish the species. 



AdelantTim occlnsus {AUcularia occlusa, Hook. f. and T.) is about a 

 third of the size of our plant, with the leaves less convex and decur- 

 rent, of firmer texture, olive-brown, whilst the stem is black and 

 polished. The leaf-cells are smaller, subquadrate, radiating in regular 

 lines from base to apex, where they are smallest. This species bears 

 a close resemblance to Nardia (AUculariaJ compressa, so that it was 

 referred by Dr. Taylor with confidence to the same genus. And yet, 

 among the Campbell Island specimens, collected by Dr. Hooker, T 

 have met with two perianths, sessile on the rhizoraatous shoots, which 

 agree in character with the fructification of A. decipiens. Guided by 

 this indication, I refer the new species to Adelantlms rather than to 

 Nardia, Gray. 



Play. Magellanica, Ldg., seems also to belong to the entire- 

 leaved section of Adelanthus, and may be known by its narrower 



F 2 



