3G() LTcnEXAcr.r. [lecanora. 



20. L. Lallavei Xvl. e.v Stiz. St. Gall. Xat. Ges. 1880, p. 347. 

 — Thallus determinate, tliickish, smooth, rimoso-areolate, siibeffigu- 

 rate at the circumference, chalky-white (K — ). Apothecia small, 

 subinnate, at first lecanorine with thin thalliue margin, at length 

 biatorine and immarginate, bright-rusty- or blood-red (K-}-dark 

 crimson); sjjores cllipsoideo-oblong, polari-bilocular, 0,008-12 mm. 

 long, 0,0(<4-7 mm. thick. — Cromb. Lich. Brit. p. 40 ; Leight. Lich. 

 Fl. p. 223, ed. 3, p. 212 (pro parte). — Ctdhpisma Lallavei Mudd, 

 Man. p. 130. t. ii. f. 44. Leckha Lallavei Clem. Ess. (18u7) 

 p. 205. 



Allied to the preceding species, but differs iu the more tartareous, milk- 

 white thallus, and the at tiist lecanorine apothecia. The thallus is 

 somelimes described as limited by a thin, dark hypothallus, but this 

 apparently belongs to a plant with which, at times, it gi'ows associated. 

 The apothecia are numerous and often crowded. 



Mab. On calcareous rocks and walls in maritime districts. — Distr. Seen 

 only very sparingly from S. and S.A\ . England and S.E. Ireland — 

 B. M. : Isle of Wight, Hampshire; St. Auitell, Cornwall. Lower Glan- 

 uiire Road, co. Cork. 



Subgeu. 5. LEPEOPLACA Xyl. Flora, 1SS3, p. 107.— ThaUus 

 leprose, soft, vitelline, sublobate. Apothecia and spermogoncs un- 

 known. 



Entirely leprarioid, having much the same relation to Placoclium as 

 Lei>roloina to Amphiloma. 



21. L. xantholyta Xyl. Flora, 1870, p. 361. — Thallus subleprose, 

 thin, crenulato-fubeffigurate at the circumfereuce, golden-citrine- 

 coloured (K-(- purplish), internally white. — Cromb. Grevillca, viii. 

 p. 112, xviii. p. 45. 



While in some respects allied to L. drrocJiroa, with which it occasionally 

 grows associattd (as al<o with L. callopisma), it at once differs iu being 

 internally white. The thallus spreads extensively ovtr the substratum 

 and is always sterile. 



Hab. On shady calcareous rocks in maritime and upland districts. 

 Distr. Local, though plentiful where it occurs, in S.W., Central, and 

 N. England, X. Wtiles, and the Central Highlands of Scotland. — B. M. : 

 Swanage, Dorsetshire ; Anstey's Cove, Torquay, Devonshire ; Bath- 

 ampton Downs, Gloucestershire ; Buxton, Derbyshire ; View Edge, 

 near Stokesav, Shropshire: Great Orme's Head, Carnarvonshire; Scout 

 Scar, AVestmorelaud. Craig Tulloch, Blair Athole, Perthshire. 



Suhgen. 6. CAXDELARIA (Mass.), Xyl. Flora, 1881, p. 454 

 {cfr. Cromb. Grevillea, xviii. p. 45). — Thallus subeffigurate or en- 

 tirely graniilose, yellow or vitelline. Apothecia lecanorine ; spores 

 8nje or numerous (12-16-32nae), ellipsoid, simple or apically 

 bilocular, rarely 1-septate ; hymenial gelatine not tinged, but the 

 apices of the thee* bluish with iodine. Spermogoncs with long 

 simple stcrigmata and straight spermatia. 



