60 COLLEMACEI. [coLLEMODIUM. 
otherwise as in the type.—Leptogium plicatile £. manor Cromb. Journ. 
Bot. 1874, p. 836; Leight. Lich. Fl. ed. 3, p. 31. 
This form evidently depends upon the nature of the habitat. It is 
rarely fertile. 
Hab. In depressions of dry rocks in maritime and upland tracts.— 
Distr. Local and rare in the 8.W. Highlands of Scotland and in S.W. 
Ireland.—B. M.: Island of Lismore, Argyleshire. Near Killarney, co. 
Kerry. 
Var. 8. hydrocharum Nyl. ev Cromb. Grevillea, xv. (1886) p. 12. 
—Thallus thicker, rigid, greyish- or glaucous-greyish ; lobes repand, 
somewhat rugulose, depressed. Apothecia central, scattered, the 
thalline margin entire-—Leptogium plicatile var. hydrocharum Nyl. 
Flora, 1875, p. 802. Collema pulposum var. hydrocharum Cromb. 
Journ. Bot. 1874, p. 147; Leight. Lich. Fl. ed. 3, p. 18. Parmelia 
hydrocharum Ach. Meth. (1803) p. 222. 
Distinguished by the colour of the thicker thallus and the more de- 
pressed lobes, which are somewhat discrete at the circumference. No 
fractification is visible in our only British specimen. 
Hab. On damp calcareous rocks in upland districts—D¢str. Only 
among the Central Grampians, Scotland.—B.M.: Craig Tulloch, Perth- 
shire. 
5. C. fluviatile Nyl. ew Cromb. Grevillea, xv. (1886) p. 12.— 
Thallus inciso-lobed, thin, greyish-green or dark greyish-glaucous ; 
lobes somewhat erect, oblong, subrepand, flexuoso-complicate, simple 
or proliferous. Apothecia small, submarginal, elevated, plane or 
somewhat concave, dark-red, the thalline margin entire, paler ; 
spores ellipsoid, usually 3-septate, 0,016-23 mm. long, 0,007-9 mm. 
thick.—Leptogium fluviatile Nyl. ew Cromb. Journ. Bot. 1874, 
p- 386; Leight. Lich. Fl. ed. 3, p. 32. Collema fluviatile Sm. Eng. 
Fl. v. p. 209; Mudd, Man. p. 40; Cromb. Lich. Brit. p.5; Leight. 
Lich. Fl. p. 24. Collema multipartitum 8. fluviatile Tayl. in Fl. 
Hib. ii. p. 109. Enchylium fluviale Gray, Nat. Arr. i. p. 397. 
Lichen fluviatilis Huds. Fl. Angl. ed. 2 (1778), p. 586; With. Arr. 
ed. 3, iv. p. 77; Eng. Bot. t. 2039. Lichenoides gelatinosum foliis 
angustioribus tuneformibus Dill. Muse. 142, t. 19. f. 28. Liche- 
nowdes gelatinosum opuntioides Dill. in Ray, Syn. ed. 3, 72. 58. 
This approaches in habit small states of Leptogium tremelloides. It is 
distinguished from the preceding species by the form of the lobes and of 
the smaller spores. In texture, as observed by Nylander (Syn. i. p. 112) 
the thallus is entirely cellular, the cortex being composed of spheroi 
cells, with the gonimia either single or usually 4-agglomerate in each 
cavity. Only a few of the British specimens seen are sparingly fertile. 
Collema rivulare Ach., according to Nylander in litt., is only a state of this 
with shorter and simple lobes; this state occurs in this country. 
Hab, On moist rocks and boulders of streams in upland mountainous 
situations.—Distr. Found only sparingly in W. and N. England, N. 
Wales, S.W. and Central Scotland, and S.W. Ireland.—B. M.: St. 
Minver, Cornwall; River Elwy, Denbighshire; Snowdon, Carnarvon- 
