74 COLLEMACEI. [lEPTOGIITM. 



ed. 3, p. 31. — CoJlema tremelloides Hook. Fl. Scot. ii. p. 72 ; Sm. 

 Eng. Fl. V. p. 213 ; Tayl. in Mack. Fl. Hib. ii. p. 111. LicJien 

 tremelloides Linn. fil. Suppl. PI. (1781) p. 450; Eng. Bot. t. 1981. 

 Lichen cochleatiis, Dicks, Crypt, fasc. i. (1785) t. 2. f. 9 ; With. Arr. 

 ed. 3, iv. p. 74. — Brit. Exs.: Cromb. n. 110; Larb. Lich. Hb. 

 n. 3. 



r apotliecia. The cortical layer is formed of rather large 

 Sparingly fertile in S.W. England and W. Ireland. 



Differs from L. laceriim in the larger smoothish thallus, leaden-coloured 

 when dry, in the more rounded lobes vrMi entire margins, and in the 

 elevated, larger 

 angular cells. 



Hah. Among mosses on moist rocks in maritime and mountainous 

 districts. — Distr. General, and usually plentiful in the Channel Islands, 

 S. and W. Britain, and E. and S.W. Ireland.— B. M. : St. Peter's Valley, 

 Island of Jersey. St. Lawrence, Isle of Wight ; near Brixhani, Saltash, 

 Haberton, Conworthy, Wembury, and Totness, S. Devon ; St. Issey and 

 near Penzance, Cornwall ; Tenby, Pembrokeshire ; Barmouth and Har- 

 lech Castle, Merionethshire; Garn, Denbigb.shire; Llanberis Pass, Car- 

 narvonshire ; Island of Anglesea. Dumbarton Castle, Dumbartonshire ; 

 Appin and Island of Mull, Argyleshire. Dunkerron Mt., Blackwater, 

 and Killarney, co. Kerry ; Kjdemore and Doughbraugh Mts., co. Galway. 



Form polyphyUum Xyl. ex Lcight. Lich. Fl. ed. 3 (1879), p. 32. 

 • — Thalline lobes smaller, mure divided and complicated, naked or 

 isidiiferous. 



The thallus of this polypbyllnus form when densely covered with isidia, 

 as it usually is, is form piclmeum (Ach. Syn. p. 343), Cromb. Grevillea, 

 XV. p. 13. Not seen fertile. 



Hab. On damp rocks among mosses in maritime districts. — Distr. Local 

 and scarce in S. England, the S.W. Highlands of Scotland, and N.W. 

 Ireland. — B. M. : Near Torquay, S. Devon. Island of Mull, Argyleshire. 

 Near Kylemore, Connemara, co. Galway. 



Subgen. 3. STEPHANOPHORUS Flot. Linntea, 1843, p. 16.— 

 Thallus crowdedly plicatulate ; apotbecia with the thalline recep- 

 tacle plicato-rugose. 



16. L. ruginosum Xyl. ex Cromb. Grevillea, sv. (1886) p. 13. — 

 Thallus membranaceous, roundly lobed, plicate, longitudinally and 

 crowdedly rugose, brownish- or greeuish-lead-colourcd, brownish- 

 black-furfuraceous on the upper surface ; lobes complicate, undulate, 

 the margins entire or crenulate. Apotbecia somewhat large, slightly 

 concave or plane, red or brownish-red, the thalline margin thick, 

 rugoso-plicate or furfuraceo-granulate ; spores ellipsoid or attenuate 

 at both apices, 3-5-scptate, and also sometimes longitudinally divided, 

 0,020-37 mm. long, 0,010-17 mm. thick. — Colltma riujinosum Duf. 

 in Schaer. Enum. (1850) p. 251. Leptocjium cldoromdinn Mudd 

 (non Xyl-)? ^lan- P- ^8; Carroll, Journ. Bot. 1867, p. 254 ; Cromb. 

 Lich. Brit. p. 9 ; Leight. Lich. Fl. p. 32, ed. 3, p. 32. 



This can scarcely, even in an infertile state, be mistaken for any other 

 British plant. It has sometimes been confounded with two exotic 



