staurothelb] verrucariace^ 311 



moderate in size, semi-immersed, soft in texture and somewhat 

 scabrid, prominent, conv^ex ; perithecial wall entire ; paraphyses 

 none ; spores 8 in the ascus, linear-oblong, colourless, at first 

 1-septate and then muriform, 0,018-34 mm. long, 0,011-17 mm. 

 thick; hymenial gelatine wine-red with iodine. — Verrucaria 

 muralis Borr. in Engl. Bot. Suppl. t. 2647, fig. 2 (1830)? 

 Leight. Angioc. Lich. p. 46, t. 20, fig. 1 (1851) (non Ach.). 

 V. hymenogonia Nyl. in Act. Soc. Linn Bord. ser. 3, i. p. 430 

 (1856); Cromb. Lich. Brit. p. 115; Leight. Lich. Fl. p. 460; 

 ed, 3, p. 491. Sphderomphale hymenogonia Mudd Man. p. 282 

 (1861). 



Exsicc. Larb. Lich. Hb. n. 199. 



Easily confused with Verrucaria muralis, as thallus and sub- 

 stratum are very similar, the perithecia, however, are rather larger, 

 and the two are readily distinguished by internal characters. 



Hah. On calcareous or arenaceous rocks, and mortar, &c. — Distr. 

 Very rare throughout the British Isles. — B. M. Mount Edgcumbe, 

 Cornwall ; Downs, Sussex ; Hyde and Cirencester, Gloucester ; New- 

 market Heath, Cambridge ; Ben Lawers, Perthshire ; Glanmire, Cork. 



Spores hrown, 1 or 2 in the ascus. 



2. St. umbrinum A. L. Sm. — Thallus brownish or dark- 

 brown, thin, smooth, unequally cracked-areolate. Perithecia 

 innate in a swelling of the thallus, the ostioles projecting ; 

 perithecial wall dimidiate ; paraphyses disappearing ; asci broadly 

 clavate, 2-spored ; spores oblong or obovate-oblong, muriform, 

 dark-brown, large, 0,045-50 mm. long, 0,018-20 mm. thick. — 

 Verrucaria lithina Ach. Meth. Suppl. p. 18 (1803)? V. umbrina 

 Fr. Lich. Eur. p. 441 (1831) (non Ach. nee Wahlenb. Fl. 

 Suec. p. 871 fide Th. Fr. Lich. Arct. p. 270); Cromb. Lich. 

 Brit. p. 109; Leighb. Lich. Fl. p. 453; ed. 3, p. 484. V.Jissa 

 Tayl. in Mackay Fl. Hib. ii. p. 95 (1836). Endocarpon 

 lithinum Leight. Angioc. Lich. p. 19, t. 6, fig. 2 (1851). 

 E. jissum Leight, tom. cit. p. 20, t. 6, fig. 3. Spheeromphale 

 umhrina Mudd Man. p. 281 (1861). 



Exsicc. Leight. n. 98 pro parte. 



Hah. On rocks in or near rivers and lakes. — Distr. Rare in upland 

 regions. — B. M. Llandyssil, Cardiganshire ; Llangollen, Denbighshire ; 

 Sunday's Well, Cork ; Ardglass, Down. 



3. St. clopima Th. Fr. Lich. Arct. p. 263 (I860).— Thallus 

 brownish, thickish, tartareous, warted-areolate, the areolae 

 somewhat tumid and rounded. Perithecia immersed in the 

 thallus, with a depressed ostiole ; perithecial wall dimidiate, 

 black ; paraphyses none ; spores 1 or 2 in the ascus, oblong, 

 colourless, becoming dark-brown, muriform, large, 0,032-53 mm. 

 long, 0,012-23 mm. thick; hymenial gelatine reddish-blue with 

 iodine. — Verrucaria clopima Wahlenb. in Ach. Meth. Suppl. p. 19 



