THROMBinw] VERKUCAEIAOE^ 307 



gelatinous, bright olive-green, the lobed margin paler and 

 yellowish; gonidia protococcoid, globose, 0,012-15 mm. in 

 diameter. Perithecia minute, crowded, globose, entire, black, 

 completely immersed in the thallus with a minute black ring 

 round the ostiole ; asci clavate ; spores ellipsoid, simple, colour- 

 less, 0,011-12 rum. long, 0,006 mm. thick; paraphyses scanty, 

 slender, cylindrical ; spermogones immersed, mixed with the 

 perithecia, with filiform straight sterigmata and simple cylin- 

 drical straight spermatia, 0,008-9 mm. long, 0,002 mm. thick. 

 — Yerrucaria Isetevirens Massee in Journ. Bot. xxx. p. 193, 

 t. 324, figs. 1-9 (1892). 



Differs from other maritime simple-spored forms in the presence of 

 paraphyses. 



Hab. On smooth rooks between tide-marks. — Distr. Somewhat 

 rare on Northern, East and West coasts (Berwick-on-Tweed, North- 

 umberland; Burnmouth, Berwickshire; Gareloch, Dumbartonshire; 

 Cumbrae, Buteshire; Loch Goil, Argyll). 



2. Thr. epigseum Wallr. Naturgesch. Flecht. p. 265 (1825) 

 (nomen) & Fl. Crypt. Germ. i. p. 294 (1831).— Thallus pale- 

 brown, or yellowish-green, thin, efi'use, gelatinous when moist, 

 somewhat f urf uraceous when dry. Perithecia small, black, globose, 

 immersed in the thallus, the upper part only visible ; perithecial 

 wall entire, thicker above ; spores oblong, ellipsoid or irregularly 

 ovate, rather large, 0,018-25 mm. long, 0,005-011 mm. thick. 

 — Sphmria epigsea Pers. Syn. Fung. Add. p. xxvii. (1801). 

 Yerrucaria epigsea Ach. Meth, p. 123 (1803); Hook, in Sm. 



. Engl. Fl. V. p. 155 ; Tayl. in Mackay Fl. Hib. ii. p. 96 ; Leight. 

 Angioc. Lich. p. 64, t. 27, fig. 4 & Lich. Fl. p. 415; ed. 3, 

 p. 446; Mudd Man. p. 293; Cromb. Lich. Brit. p. 116. Lichen 

 terrestris Sm. Engl. Bot. t. 1681 (1807). Inoderma epigsea 

 S. F. Gray Nat. Arr. i. p. 498 (1821). 



Hab. On soil. — Distr. Bather rare throughout the British Isles. — 

 B. M. Hassocks, Maresfield and Tilgate, Sussex ; Cradley, Hereford- 

 shire ; Hales End near Malvern, Worcestershire ; Boss, Clare ; 

 Connemara, Galway. 



3. Thr. thelostoma A. L. Sm. — Thallus reddish-brown, bhin, 

 continuous, minutely cracked-areolate, suborbicular and deter- 

 minate. Perithecia reddish-brown, sessile, hemispherical, becom- 

 ing widely depressed round the ostiole ; perithecial wall entire, 

 reddish-brown above, paler below ; paraphyses slender, thread- 

 like, sometimes branched ; spores ellipsoid, colourless, 0,017-20 

 mm. long, 0,009-010 mm. thick, or sometimes rather larger. — 

 Yerrucaria tJielostoma Ach. ex Harrim. in Winch Bot. Guide 

 ii. p. 44 (1807); Mudd Man. p. 293; Leight. Lich. Fl. p. 421 ; 

 ed. 3, p. 452. Lichen thelostomus Sm. Engl. Bot. t. 2153 (1810). 

 Pyrenula umhonata Ach. Lich. Univ. p. 316 (1810); S. F. Gray 

 Nat. Arr. i. p. 493. Segestria thelostoma Fr. Lich. Eur. p. 429 



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