ACROCORDIa] PYRENULACEiE 313 



Asci clavate or ovate, spores more or less 

 massed. 

 Spores colourless. 



Spores elongate - fusiform, 1-5- 



septate 118. Arthopyrenia. 



Spores elongate - acicular, multi- 



septate 114. Leptorhaphis. 



Spores brown. 



Spores 1-5 -septate 115. Microthelia. 



Paraphyses unbranched, distinct. 



Spores colourless 1-5-septate. 



8 in the ascus 116. Porina. 



Many in the ascus 117. Thelopsis. 



Spores brown. 



Spores 1-5-septate with short cells 118. Pyrenula. 

 Perithecia often united. 



Spores brown, muriform 119. Anthracothe- 



cium. 



112. ACROCORDIA Massal. Gen. Lich. p. 17 (1854). (PL 47.) 

 Thallus crustaceous. Perithecia simple, globose or semi- 

 globose and somewhat conical, black, semi-immersed ; paraphyses 

 persistent, slender, branched and entangled ; asci cylindrical 

 oblong, 8-spored ; spores uniseriate in the ascus, ellipsoid, 1 -septate, 

 colourless. Spermogones small, globose, with rod-like spermatia. 



Distinguished by the elongate narrow asci with the spores in a 

 straight or oblique row. 



1. A. gemmata Koerb. Syst. Lich. Germ. p. 356 (1855). — 

 Thallus white or greyish-white, thin, nearly smooth or somewhat 

 pulverulent, continuous or sometimes cracked, effuse or limited 

 by a dark hypothallus. Perithecia black, large, prominent, hemi- 

 spherical, immersed at the spreading base, usually with a papillate 

 ostiole ; perithecial wall dimidiate with an inner thin brown 

 entire layer ; paraphyses long, slender ; spores broadly oblong, 

 1-septate, colourless, 0,015-29 mm. long, 0,007-0,013 mm. thick. 

 — Lichen gemmatus Ach. Lich. Suec. Prodr. p. 17 (1798). Verru- 

 caria gemmata Ach. Meth. p. 120, t. 3, fig. 1 (1803); Borr. in 

 Engl. Bot. Suppl. t. 2617, fig. 2; Hook, in Sm. Engl. Fl. v. 

 p. 150; Tayl. in Mackay Fl. Hib, ii. p. 89; Leight. Angioc. 

 Lich. p. 43, t. 18, figs. 4 & 5 & Lich. Fl. p. 430; ed. 3, p. 462 ; 

 Cromb. Lich. Brit. p. 118. Lejophlea (jemmata S. F. Gray Nat. 

 Arr. i. p. 496 (1821). Thelidium geimnatum Mudd Man. p. 297 

 (1861). 



Exsicc. Carroll Lich. Hib. n. 33; Larb. Lich. Hb. n. 196; 

 Mudd n. 285 ; Leight. n. 136. 



Hab. — On trunks of trees. — Distr. Common throughout the 

 Channel Islands, England, Wales, and S. and S.W. Ireland ; rare in 

 Scotland. — B. M. Trinity, Jersey ; Lanhydrock Park, Cornwall ; 

 Torquay, Devon ; near Brighton, Erringham, Wiston and Woodman - 

 cote, Sussex ; near Lyndhurst, New Forest, Hants ; Batheaston, 

 Somerset ; near Cirencester, Gloucestershire ; Thorndon Hall, Wal- 



