514 



LTCHEXACEI. 



[thelotrema. 



p. 45. — Lichen hpadinus Ach. Prodr. (1798) p. 30. Lichen in- 

 cJmus Eng. Bot. t. 678. — Brit. Exs. : Leight. n. 121 ; Mudd, 

 n. 268. 



X-30 



X 250 



Fig. 73. 



Tkelotrema lepadimnn kch. — A. Section of apotbecium, x30. B. Theca and 



paraphyses, x250. C. Two spores, X350. 



The thallus varies somewhat in thickness, and at times, especially 

 when growing on holly, is determinate and marked bv a narrow, black, 

 hypothalline line. In a young state the apothecia might be taken for 

 those of a Pertiisaria, but when fully deyeloped they are very different 

 in appearance. They are usually more or less scattered, but occasionally 

 in old plants become crowded. 



Hab. On smooth bark of trees from maritime to upland tracts. — Distr. 

 General and common in England ; rai'er in Scotland ; apparently very 

 rare in Ireland. — B. M. : Ugley and AValthamstow, Essex ; Ighthani, 

 Kent ; St. Leonard's Forest, Sussex ; Xew Forest, Hants ; Ilsham Walk, 

 Torquay, S. Devon ; St. Breock, Cornwall ; Bagley Wood, Berks ; 

 Bardon Hill, Leicestershire ; HoUybush Hill, Malvern, Worcestershire ; 

 Cwm Bychan and Barmouth, Merionethshire ; Hafod, Cardiganshire ; 

 Haughmond Hill, Church Sti-etton, and Acton Burnel Hill, Shropshire ; 

 Baysdale, Cleveland, Yorkshire; Teesdale, Durham; Calder Abbey, 

 Cumberland; Feltou Woods, Northumberland. Foot of Ben Lomond, 

 Dumbartonshire ; Barcaldine and Appiu, Argyleshire ; Glen Falloch and 

 Loch Katrine, Perthshire ; Morrone, Braemar, Aberdeenshire. River- 

 stone, CO. Cork ; Killarney, co. Kerry. 



Var. /3. scutelliforme Ach. Lich. Univ. (1810) p. 312; Syn. 

 p. 115. — Thallus effuse, thickish, unequal, at times subpulverulent, 

 cream-coloured. Apothecia prominent, somewhat large, crowded, 



