BRITISH HEPATIC^, 03 



a slender variety of P. spinulosa, the shoots of which had evidently grown amongst 

 dense herbage, and formed probably part of the tuft communicated to Hooker. In this 

 form the leaves are narrower, more distant, and irregularly denticulate; and some ot 

 the colesules (especially near the base) appear naked from the decay of the involucral 

 bracts. 



It is a curious circumstance that fructification has never been met with, although 

 in the south of Ireland jj and $ plants. are not unfrequently found together. Pro- 

 bably, if looked for at an earlier period of the year, the capsules would be found ; but 

 few skilled botanists visit the likeliest spots until later in the season. 



Those who have formed their opinion .of the species from English specimens only, 

 can form no idea of the variety and luxuriance of its development in the Killamey 

 woods. There, within a few feet of each other, it is possible to collect not only the 

 forms I have attempted to describe, but numberless others. Like most plants propa- 

 gated by flagellse or gemmse, the species is subject to much variation. Some of the 

 minute, microphyllous forms are especially puzzling. Looking at the diversities which 

 undoubtedly occur in the same species, it is impossible to receive without doubt many 

 of the exotic species formed from single or barren specimens only. 



P. punctata^ Taylor, appears to me to be the typical form, in which the leaves 

 are more crowded, of firmer texture, more distinctly spinose, and filled with chlorophyll, 

 so as to appear punctate under the lens. 



Pl. IV. Pig. 14. P. spinulosa. 1. Portion of var. a x 8. 2. Terminal shoot 

 of (i X 16, inferior aspect. 3, 8. Stem-leaves x 16. 4:. Leaf from /3, showing the 

 punctate a/reolce. 5. Involucral leaf. 6. Apex of $ shoot. 7. Perigonial leaves 

 enclosing antheridia. 9. Golesule. 10. PistiUidium Q)a/rren). 11. Leaf-cells x 250. 



N.B. — The line separating the middle from the lower right-hand figures should 

 have been left out. 



4. Plagiochila tridenticulata, Taylor. 



Plate III. Fig. 10. 



Stolons creeping, rigid, radiculose ; shoots loosely tufted, ascend- 

 ing, irregularly branched ; leaves rather distant, alternate, obliquely 

 patent-divergent, cuneate-obovate ; margins entire, apex deeply bi- 

 tri-fid, segments acute, divergent ; male spikes ovate ; fructification ? 



Jung, spinulosa /3 tridenticulata, Hook. Jung. p. 9, t. xiv. ff. 9, 10 (exclus. syn. 

 J. tridenticulata, Mich.) ; H. British Flora, ii..p. 108 ; Lindenb. Hep. Eur. p. 78, n. 73 ; 

 Mackay, Fl. Hib. ii. p. 58, n. 10, v. minuta. 



Padula corniculafa, Dumort. Syll. Jung. p. 15. 



Plag. spimdosa /3, Lindenb. Spec. Hep. Plag. p. 6 et p. 154, t. i. f 7, 8. 



Flag, tridenticulata, Dumort. Eev. Jung. p. 15 (1835) ; Taylor in G. L. N. Syn. 

 Hep p 26 (1844) ; Carr. Irish Cryp. Tr. Ed, Bot. s. vii. p. 446, t. xi. f. 5 ; Dum. Hep. 

 Eur. p. 45, n. 6 (1874) ; G. & E. Hep. Eur. Ex. n. 212. 



Martinellia spirmlosa j3 tridenticulata, Gr. Nat. Arr. i. p. 692, n. 8. 



J. spinulosa y* foliis minutis apice bidentatis, G. Lyell. 



Hab. Mountains near Bantry, Miss Hutchins and Mackay ! Scotland, W. Wilson ! 

 Kenswick, C. Lyell, 1812 ! Tore Cascade and Upper Lake, Killamey, &c., 1861 ; 

 Gleng^riflfe, Sept. 1869 ! Brandon Mountain, Dr. Moore I Aberwater, and Dolgelly, 

 N. Wales, W. Wilson. 



