66 BRITISH HEPATTC.3S. 



Obs. — No trace of either male or fertile fructification has been found on this plant. 

 "Whether, therefore, it «honld be associated with the present ~ genus, or deserves to be 

 looked upon as generically distinct, is still questionable. 



The specimens ■which have ' come under my examination have been very meagre, 

 and when mingled with P. tridenticulata, which is not un^requently found associated 

 with it, creeping among the fronds of FruUania, &c., it is no easy matter to dis- 

 criminate between the two. 



In the creeping habit, size, and the form of its leaves, it approaches J. cimeifolia, 

 another rare Irish species, the position of which is doubtful, from the absence either of 

 (J or ? inflorescence. 



Pl. IV. Fig. 13.— P. exigua. 1. Natural size. 2. Shoot x 20. 3, 3. Stem- 

 leaves. 4, 5. The same showing cell-structv/re. 6. Apex of shoot and terminal amphi- 

 gastria. 7. Amphlgast/ria. 



IX. Mylia, Gr. 8r JB., emend. 



Pl. IX. Figs. 29, 30. 



Jungermannia, Hook. Brit. Jung. p. 15, nn. 46 and 47, tt. 24 et 57 (1816). 



Mi,Uus, Gr. & B. in Gray's Nat. Arr. i. p. 690 (1821). 



Aplozia, Dumort. Syll. Jung. p. 48 (1831). 



Lepioseyphus, Mitt, in Hook. Lond. Jour, of Bot. iii. p. 358 (1851). 



Leioscyphm, Mitt, in Hook. Fl. Nov. Zeal. ii. p. 134 (1855). 



C'oleochila, Dumort. Hep. Eur. p. 105 (1874). 



Dioicous; Colesule terminal (or from the growth of innova- 

 tions axillary), ovate-oblong, latierally compressed from a sub- 

 terete base ; apex contracted, truncate, at length bilabiate, den- 

 ticulate. 



Involucral bracts two, patent from a clasping base ; bracteole 

 lanceolate, unidentate, free. 



Capsule ovate, coriaceous, quadrivalved. 



Elaters deciduous, bispiral. 



Perigonial leaves usually narrower, ventricose, clustered near the 

 apex of distinct shoots. Antheridia two, roundish. 



Plants forming dense tufts in alpine bogs, or more thinly scat- 

 tered and clinging to the stems of Sphagnum. Shoots simple or 

 innovant below the apex, erect or creeping, tomentose beneath. 

 Leaves succubous, bifariously imbricated, alternate, semi- vertical, 

 either circular or ovate and pointed. Amphigastria subulate, 

 obscured by the rootlets, except at the apex of the shoots. 



Etym. Melius, the name of a botanist mentioned in the Nova 

 Genera Michelii (1729). 



Obs. — In Mylia we find the compressed colesule of Plagiochila, associated with the 

 general habit of Jungermannia. 



Under Leioscyphus Mitten has grouped together plants differing widely in cha- 

 racter. I have been favoured by Dr. Spruce (14th July, 1874) with the subjoined 

 synopsis of species in which the colesule is compressed, wide-mouthed, truncate, and 

 more or less bilabiate : — 



