312 PYRENOCARPEI [STAUROTHRLE 



(1803); Carroll in Journ. Bot. iii. p. 292 (1865)? Leight. Lich. 

 Fl. ed. 3, p. 485. 



Differs from the preceding in tlie form and development of the 

 thalliiB. A specimen in the Britisli Museum from Dawros River, 

 collected by Larbalestier and recorded by him under this species, is 

 Verrucaria viridula. 



Hah. On rocks in or near rivers. — Distr. Rare in W. Ireland, 

 Dawros River, Connemara, Galway. 



Spores brown, 4-8 in the aacus. 



4. St. rupifraga Arn. in Verb. K.K. Zool.-Bot. Ges. xxx. 

 p. 149 (1880). — Thallus dark-bluish-grey or whitish, or smoky- 

 brown, tartareous-farinose, eftuse, thin, sometimes evanescent 

 Perithecia small, globose, immersed in the rock or emergent, 

 leaving pits, somewhat plane above, the ostiole a minute pore ; 

 perithecial wall entire ; paraphyses disappearing ; spores 4-8 in 

 the ascuSj ovoid-oblong, becoming dark-reddish-brown, muriform, 

 0,036-55 mm. long, 0,012-20 mm. thick; hymenial gelatine 

 wine-red with iodine. — Sagedia ealcarea Deakin in Ann. Mag. 

 Nat. Hist. ser. 2, xiii. p. 39, t. 4, fig. 12 (1854)? Polyhlastia 

 rwpifraga Massal. Symm. Lich. p. 100 (1855). Verrucaria umhrina 

 var. ealcarea Nyl. in Act. Soc. Linn. Bord. ser. 3, i. p. 426 

 (1856) ; Cromb. Lich. Brit. p. 109. V. rupifraga Nyl. ex Cromb. 

 Lich. Brit. p. 109 (1870) ; Leight. Lich. Fl. p. 456 ; ed. 3, p. 488. 

 F. ferehrata Leight. Lich. Fl. p. 456 ; ed. 3, p. 488. Sphserom- 

 phale terehrata Mudd Man. p. 281 (1861). 



Sometimes the perithecia are so immersed as to be visible merely 

 as minute black points in the stone. The spores are divided into 

 small cells without any definite transverse septa. 



Hah. On calcareous rocks. — Distr. Rare in W. England, N. Scot- 

 land and W. Ireland.- — B. M. Sapperton, Gloucestershire ; Craig Guie, 

 Braemar, Aberdeenshire ; Kylemore, Connemara, Galwa3\ 



PYRENULACEiE. 



Thallus crustaceous, superficial or developed within the sub- 

 stratum, not corticated. Algal cells Trentepohlia. Perithecia 

 simple, globose or semi-globose, more or less immersed, opening 

 by a pore at the apex (ostiole). Sperm ogones small, globose or 

 ovoid, with simple or sparingly branched sterigmata and sper- 

 matia produced apically. 



Distinguished by the yellowish filamentous gonidia {Trentepohlia), 

 and also by the almost constantly persistent paraphyses. There are 

 eight genera represented in the British Islands : — 



Perithecia scattered. 



Paraphyses branched, entangled or wanting. 

 Asci cylindrical, spores uniseriate. 



Spores 1 -septate 112. Aerocordia. 



