opegrapha] graphidacevE 237 



spores somewlicat clavate, colourless, sometimes becoming brov/iiish, 

 3-septate, 0,014-18 mm. long, 0,004-G mm. thick.— 0. saxatilis 

 Fr. Lich. Eur. p. 366 (1831), pro parte (non DC.) ; Hook, in Sm. 

 Engl. Fl. V. p. 145 pro parte ; Tayl. in Mackay Fl. Hib. ii. p. 106. 

 0. Chevallieri Leight. in Ann. Mag. Nat. Hist. ser. 2, xiii. p. 90, 

 t. 5, f. 4 (1854) (excl. syn.) ; Mudd Man. p. 228 (excl. syn.). 

 0. atra var. calcarea Stiz. in Nov. Act, Acad. Leop. -Carol. 

 xxxii. 4, p. 18, t. 1, f. 5, a-d (1865) ; Cromb. Lich. Brit. p. 98 ; 

 var. ChevalUeri Stiz. Z. c. p. 20, t. 1, £. 5, t-z ; Cromb. I. c. 

 0. saxicola var. Chevallieri Leight. Lich. Fl. p. 379 ; ed. 3, p. 402. 

 Hysterina calcarea S. F. Gray Nat. Arr. i. p. 505 (1821). 



Exsicc. Leight. nos. 67, 242 ; Mudd n. 203 ; Larb. Lich. Hb. 

 n. 275. 



Differs from 0. confluens in the white and usually more developed 

 thalius, the more crowded and conglutinate paraphyses and the thick 

 apex of the ascus. 



Hah. On rocks mostly calcareous or arenaceous, rarely on clay 

 soil. — Distr. General throughout the Channel Islands and England, 

 rarer in Scotland and Ireland. — B. M. St. Ouen's Bay, Jersey ; 

 Bodmin, Cornwall ; Kingsbridge and Torqua.y, Devon ; Ventnor, I. of 

 Wight ; Ardingly, Hastings and Keymer Church, Sussex ; near 

 Cirencester, Gloucestershire ; Bathampton, Somerset) ; Hereford ;. 

 Leigh Court, Worcestershire ; Giltar Point, Tenby, Pembrokeshire ; 

 Aberdovey, Merioneth ; Holyhead, Anglesey ; Great Orme's Head, 

 Carnarvon ; Castell-Dinas-Bran, Denbighshire ; Parson Drove, Cain- 

 bridgeshire ; Bay of Nigg, Kincardineshire ; Kilbarrick Church, near 

 Dublin ; Pioss and lOlkee, Clare ; Glenarm, Antrim. 



Form heteromorpha A. L. Sm. — Thalius almost obsolete. 

 Apothecia more scattered than iti the species and the groups 

 smaller, rather large and prominent, simple or sometimes 

 branched ; internal structure similar. — Opegrajpha atra var. 

 Chevallieri f. heteromorjphct Stiz. tom. cit. p. 21, t. 1, f. 5, a-^. 

 0. atra f. heteromorpha Cromb. Lich. Brit. p. 98 (1870). 0. saxi- 

 cola var. Chevallieri f. heteromorpha Leight. Lich. Fl. ed. 3, p. 402. 



Exsicc. Larb. Lich. Hb. n. 77. 



Hah. On maritime rocks. — Distr. Bare in the Channel Islands, 

 S. England, E. and W. Scotland and S. and W. Ireland.— B. M. 

 Port Moulin, Sark ; Noirmont, Jersey ; Wembury, Devon ; Aberdovey, 

 Merioneth ; Bay of Nigg, Kincardineshire ; near Peterhead, Aberdeen- 

 shire ; Barcaldine, Argyll ; Old Head of Kinsale, and Rostellan, Cork ; 

 Twelve Pins and Killery, Connemara, Galway. 



12. 0. confluens Stiz. in Flora xlviii. p. 75 (1865).— Thalius. 

 greyish-green, effuse, thin or wanting. Apothecia usually 

 grouped in little masses, rarely solitary and scattered; sessile 

 simple, rather thick, cylindrical, straight or curved and contorted ; 

 disc slit-like, becoming somewhat open, the margins rounded, 

 inflexed, becoming acute ; paraphyses discrete, slightly swollen 

 and brown at the tips ; spores colourless, elongate-ovate, 3-septate, 



