126 LECANO-LECrDEEI [bIATOEINA 



L. Lauren Leight. Lich. Fl. ed. 3, p. 314 (1879). Gatillaria 

 Laureri Hepp in Arn. exs. n. 353 (1867). 

 Exsicc Johns, n. 337. 



On the bark of trees, chiefly beech, rare. — B. M. Lyndhurst, Kew 

 Forest, Hants. 



28. B. lenticularis Koerb. Syst. Lich. Germ. p. 191 (1855). 

 — ThaUiis thin, effuse or evanescent, brownish or greyish (K — , 

 CaCl — ). Apothecia smaU, adnata, reddish-brown or black, plane 

 with a prominent margin becoming convex and immarginate ; 

 hypothecium brownish or colourless; paraphyses slender, distinct, 

 brown or blackish-brown at the capitate tips ; spores oblong, small, 

 0,006-11 mm. long, 0,002—4 mm. thick; hymenial gelatrae blue 

 then wine-red with iodine. — Lecidea lenticularis Ach. Sju. p. 2S 

 (1814)?; Cromb. lich. Brit. p. 91 pro parte (excl. syn. <fe subsp. 

 nigroelavata) ; Leight. Lich. Fl. p. 315; ed. 3, p. 335 (excl. 

 f. nigrodavata). L. umhrinella ^S'yl. in Flora hx. p. 309 (1876) ; 

 Cromb. in GreviUea v. p. 27 ; Leight. Lich. Fl. ed. 3, p. 327. 

 Zeora lenticularis Flot. ia TJebers. Schles. Gtes. Vaterl. Cult. p. 124 

 (1850). 



Exsicc. Larb. Lich. Hb. nos. 70, 112, 314; Johns, n. 394. 



Distinguished by the small size of the apothecium and its contents, 

 and especially by the almost globose tips of the paraphyses, the upper 

 part of which is coloiored dark-brown, resembling those of Lecidea 

 nigrodavata which has been classified by several authors as a variety 

 of this species, but is included in Lecidea on account of the con- 

 stantly simple spores. Several varieties in addition to those recorded 

 have been distinguished — var. acrusta^ea, Hepp (ex Arnold in Flora xli. 

 p. 502 (1858) ; Leight. Lich. Fl. ed. 3, p. 336 as form) represents a con- 

 dition with evanescent thaUus ; var. vulgaris Koerb. (Par. Idch. p. 144 

 (1860) ; Leight. I. c. p. 835 as form) as understood by Leighton differs 

 from the type in including only those with a distinct thallus ; f . oxydata 

 Leight. Q. c. p. 336) has a ferruginous-ochraceous thaUus, and is 

 probably identical with var. enibescens. 



Bah. On rocks in maritime and upland districts. — Distr. Not 

 unfrequent throughout the British Isles. — B. M. La Moye, Jersey ; 

 Anstey's Cove, Torquay, Devon ; Bathampton Downs, Somerset ; 

 Beachy Head, Sussex ; Bisley and near Cirencester, Gloucestershire ; 

 Llanymynech Hill, Shropshire; Bangor and Snowdon, Carnarvon- 

 shire ; St. Bees, Cumberland ; Lismore, Argyll ; Craig Guie, Braemar, 

 Aberdeenshire; near Cork Harbour; Blackwater Bridge and Dinish, 

 Kerry ; KiUree, Clare ; Kylemore Lake and Lettermore, Connemara 

 and Tully, Galway. 



Form nigricans Arnold in Flora xliii. p. 74 (1860). — ThaUus 

 blackish, thm, furfuraceous, areolate, plane. Apothecia slightly 

 larger than in the type, black. — Lecidea lenticularis f. nigricans 

 Leight. Lich. Fl. ed. 3, p. 336. 



The form rimoso-areolata (Leight. I. c.) agrees with this in the 

 dark areolate thallus and blacki^ apothecia. In Larbalestier's 

 specimen the thallus is very much broken up and located in the 

 crevices of the rock, and is a slightly thicker state of f. nigricans. 



