ARTHONIA] ARTHONIACEiE 213 



— B. M. Becky Falls, Devon ; Barmouth, Merioneth ; Pontesbur,)', 

 Shropshire ; Baysdale, Cleveland and Farndale, Yorkshire ; Dinish, 

 Killarney, Kerry. 



13. A. arthonioides A. L. Sm. — Thallus rather thick, cream- 

 coloured slightly tinged with rose, effuse, smooth becoming 

 pulverulent. Apothecia small, numerous, solitary or rarely 

 confluent, rounded, somewhat convex, immarginate, the disc 

 rough and pulverulent when old ; spores G-8 in the ascus, linear- 

 clavate, 3-septate, the upper cell slightly larger, 0,013-16 mm. 

 long, 0,006-7 mm. thick ; hymenial gelatine yellowish-red with 

 iodine. — A. trachjlioides Nyl. in Mem. Soc. Sci. Nat. Cherb. iv. 

 p. 99 (1856) ; Mudd Man. p. 251, t. 4, f. 98 ; Cromb. Lich. Brit, 

 p. 104; Leight. Lich. Fl. p. 398; ed. 3, p. 421. Lecidea artho- 

 nioldes Ach. Lich. Univ. p. 178 (1810). 



Exsicc. Mudd n. 237. 



Hah. On rocks. — Distr. Rare in subalpine or mountainous 

 districts. — B. M. Great Orme's Head, Carnarvonshire ; Ingleby and 

 Highcliff, Cleveland, Yorkshire. 



14. A. dendritica A. L. Sm. — Thallus whitish or greyish, 

 effuse, tartareous, rather thick in places, smooth. Apothecia 

 black, innate, roundish or somewhat elongate and irregularly 

 radiate, contiguous and confluent or solitary, plane, internally- 

 pale ; asci pyriform ; spores obovate, or clavate, colourless, 2-4- 

 septate, upper cell largest, 0,017-22 mm. long, 0,005-7 mm. thick. 

 —Stigmatidium dendriticum Leight. in Journ. Bot. xiii. p. 257, 

 t. 166 (1875) & Lich. Fl. ed. 3, p. 413. 



Exsicc. Larb. Lich. Hb. n. 192. 



Resembles Entcrographa in the grouping of the apothecia, but 

 is separated from that genus b^^ the form and structure of asci and 

 spores. 



Hah. On rocks. — Distr, Very rare in W. Ireland. ^x5. M. Tally 

 and Doughruagh Mt., Connemara, Gal way (the only localities). 



15. A. ilicina Tayl. in Mackay Fl. Hib. ii. p. 105 (1836).— 

 Thallus cream-coloured, thin, smooth, shining, limited by a 

 brownish border varying in width. Apothecia small, scattered, 

 subimmersed, irregularly round or oblong, blackish-brown, plane ; 

 spores colourless or pale yellow, obovate-clavate, 6-septate, the 

 upper cell largest, 0,021-36 mm. long, 0,009-12 mm. thick ; 

 hymenial gelatine blue, the asci yellowish or wine-red, with 

 iodine.^ — Leight. in Ann. Mag. Nat. Hist. ser. 2, xiii. p. 441, 

 t. 8, f. 36 (1854) & Lich. Fl. p. 401 ; ed. 3, p. 425 ; Mudd Man. 

 p. 248 ; Cromb. Lich. Brit. p. 102. A. ilicinella Nyl. in Flora 1. 

 p. 179 (1867) ; Carroll in Journ. Bot. v. p. 259 (1867) ; Cromb. 

 /. c. Leight. Lich. Fl. II. c. A. siihexcedens Nvl. in Flora Ixii. 

 p. 221 (1879) ; Cromb. in Grevillea viii. p. 29. 



