60 COLLEMACEI. [COLLEMOBIUM. 



otherwise as in the type. — Leptoiimm plicatile f. minor Cronib. Jouni. 

 Bot. 1874, p. 336 ; Lcight. Lich. Fl. ed. 3, p. 31, 



This forui evidently depends upon the nature of the habitat. It is 

 rarely fertile. 



Huh. In depressions of dry rocks in maritime and upland tracts. — 

 Distr. Local and rare in the S.A\'. Highlands of Scotland and in S.W. 

 Ireland. — B. M. : Island of Lismore, Argyleshire. Near Killarney, co. 

 Keny. 



Var. i3. hydrocharum Xyl. ex Cromb. Grevillea, xv. (1886) p. 12. 

 — Thallus thicker, rigid, greyish- or glaucous-greyish ; lobes repand, 

 somewhat rugulose, dejjressed. Apothecia central, scattered, the 

 thalline margin entire. — Leptogium pUcatile var. hijtlrocharam Nyl. 

 Flora, 1875, p. 302. Collema pidposum var. hydrocharum Cromb. 

 Journ. Bot. 1874, p. 147 ; Leight. Lich. Fl. ed. 3, p. 18. Famielia 

 hydrocluvrum Ach. Math. (1803) p. 222. 



Distinguished by the colour of the thicker thallus and the more de- 

 pressed lobes, which are somewhat chscrete at the circumference. No 

 fructiheation is visible in our only British specimen. 



Hub. On damp calcareous rocks in upland districts. — D/'Mr. Only 

 annmg the Central Grampians, Scotland. — B. M. : Craig TuUoch, Perth- 

 shire. 



5. C. fluviatile Nyl. ex 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-rod, the thalline margin entire, paler ; 

 spores ellipsoid, usually 3-septate, 0,016-23 mm. long, 0,007-9 mm. 

 thick. — Leptor/ium jiuviatile Nyl. ex Cromb. Journ. Bot. 1874, 

 p. 336 ; 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 midtipartitum 1^. Jiuviatile Tayl. in Fl. 

 Hib. ii. p. 109. EncJiyliion fluviale Graj^ Nat. Arr. i. p. 397. 

 Lichen jluviatilis Huds. Fl. Angl. ed. 2 (1778), p. 536 ; With. Arr. 

 ed..3, iv. p. 77 ; Eng. Bot. t. 2039. Lichenoides gelatinosum foliis 

 angustiorihus tunceformibtis Dill. Muse. 142, t. 19. f. 28. Liche- 

 noides gelatinosum opuntioides Dill, in Kay, Syn. ed. 3, 72. 58. 



This approaches in habit small states of Leptogium tremeUoides. 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. 11:2), 

 the thallus is entirely cellular, the cortex being composed of spheroid 

 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 rivuUire Ach., according to Nylander m Hit., is only a state of this 

 with shorter and simple lobes ; this state occurs in this country. 



Huh. 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 Cftntral Scotland, and S.W. Ireland.— B. M.: St. 

 Minver, Cornwall ; lliver Elwy, Denbighshire ; Suowdon, Carnarvon- 



