30G LICHENACEI. [rUYSCU. 



numerous, and the spermogones, -wliich are not uncommon, have the 

 spermatia equally cylindrical, 0,006 mm. long, about 0,001 mm. thick. 



Hab. On the trunks and branches of trees, and on old pales, rarely 

 eiTatic on stone walls, chiefly in cultivated lowland and upland districts. 

 — Distr. General and common throughout Great Britain and probably 

 Ireland, becoming rare in X. Scotland : rare in the Channel Islands. — 

 B. M. : Island of Guernsey. Bury St. Edmunds, Suftblk ; Epping Forest, 

 Essex ; Edgeware, Middlesex ; Hurstpierpoint and Lewes, Sussex ; near 

 Eyde, Isle of Wight ; Wembury, Devonshire ; near "Withiel, Cornwall ; 

 Bourn, Cambridgeshire ; Milton, Oxfordshire ; Bolton Abbey, Lincoln- 

 shire ; Twycross, Leicestershire ; Moor Park, Herefordshire ; Crowle, 

 AV^orcestershire ; near Shrewsbury, Shropshire : Aberdovey and Anglesea, 

 N. "Wales ; Ayton, Cleveland, Yorkshire : Middleton, Teesdale, Durham ; 

 Kendal, Westmoreland. Largs, Ayrshire; near Edinburgh: Appin, 

 Argyleshire; Killin and Blair Athole, Perthshire; Cults, near Aberdeen, 

 and Abergeldie Castle, Aberdeenshire ; Applecross House, Ross-shire ; 

 Carrigaloe and Aghada, co. Cork ; Ballynegarde, co. Limerick ; Dun- 

 kerron, co. Kerry. 



Form 1. panniformis Cromb. Journ. Linn. Soc. Bot. xvii. (1880) 

 p. 571; Journ. I3ot. lbS2, p. 273. — Thallus with the laciniai short, 

 crowded, densely imbricate. Apothecia small. — Lichenoides gJaucum 

 orhicvlare, scfjmentis latiuscidis, scuteUis nigris Dill. Muse, 177, t. 24. 

 f. 71 D. 



One of those panniform conditions of foliaceous lichens which have 

 recently been noted, forming as it were a thickish congested crust, the 

 lacinise presenting their uonnal appearance only at the extreme circum- 

 ference of the thallus in entire specimens. In the fertile plants seen, the 

 apothecia are few and small, with the receptacular margin thickish. 



Hah. On the trunks of old trees in upland districts. — Di>>ty. Only in 

 W. England and among the Central Grampians, Scotland. — B. M. : Har- 

 boro' Magna, Warwickshire. Craig Tulloch, Blair Athole, Perthshire. 



Form 2. deminuta Cromb. Journ. Bot^l882, p. 273.— Thallus 

 efi'use, more or less diffract, the lacinia) minute. Apothecia very 

 small, pruinose. 



Probably only a starved condition of the preceding form, in which the 

 laciniae are either somewhat congested or scattered. In our few speci- 

 mens the apothecia are, with one exception, veiy sparingly present. 



Ilab. On the trunks and branches of trees in maritime and upland dis- 

 tricts.— -D/s^r. Only sparingly in S. and W. England, S. Wales, and the 

 Channel Islands. — B. M. : Island of Guernsey. Shanklin and Appuldm- 

 combe. Isle of Wight ; near Cirencester, Gloucestershire ; Dolgelly, 

 Meriouethshii'e. 



Form 3. argypliea Kyi. Lich. Scand. (18C1) p. lOJ.— Thallus 

 entirely wbite-pruinose ; lacinioc somewhat firm and slightly dilated 

 at the circumference. Apothecia constantly pruinose, the receptacle 

 often unequal or sometimes subcrenulate. — Cromb. Journ. Linn. Sec. 

 Lot. xvii. p. 571. — Farwelia indveridenta ft. arrfyiJua Ach. Lich. 



