opEgrapha] geaphidace*; 237 



spores somewhat clavate, colourless, sometimes becoming brownisli, 

 3-septate, 0,014-18 mm. long, 0,004-6 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 (exol. 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. Ghevallieri Stiz. I. c. p. 20, t. 1, f. 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 O. confluens in the white and usually more developed 

 thallus, the more crowded and conglutinate paraphyses and the thick 

 apex of the ascus. 



Hab. 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 Torquay, Devon ; Ventnor, I. of 

 Wight ; Ardingly, Hastings and Keymer Chm:ch, 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, Cam- 

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

 Dublin ; Boss and Kilkee, Clare ; Glenarm, Antrim. 



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

 Apothecia more scattered than in the species and the groups 

 smaller, rather large and prominent, simple or sometimes 

 branched ; internal structure similar. — Opegrapha atra var. 

 Chevallieri i. heteromorpha Stiz. torn. cit. p. 21, t. 1, f. 5, a-f. 

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

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



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



Hab. On maritime rooks. — Distr. Bare in the Channel Islands, 

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

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

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

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

 Twelve Pins and KUlery, Connemara, Galway. 



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

 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, 



