arthonia] arthoniace.e 211 



6. A. elegans Ach. Lich. Univ. p. 135, t. ], fig. 1 (1810) 

 emend. ; Almqu. in K. Svensk. Vet.-Akad. Handl. xvii. n. 6, 

 p. 19. — Thallus whitish, thin. Apothecia dark -coloured, och- 

 raceous-pruiiiose, roundish or some\vhat difform ; spores obovate, 

 3-septate, upper cell largest, 0,015-18 ram. long, 0,007-8 mm. 

 thick. — A. odiracea Duf. in Journ. Phys. Ixxxvii. p. 205 (1818); 

 Carroll in Journ. Bofc. iii. p. 291 (18G5) ; Cromb. Lich. Brit, 

 p. 102; Leight. Lich. Fl. p. 394; ed. 3, p. 418. 



Differs from A. gr eg aria in the apothecia and in the smaller 

 spores. Alniquist fails to note that the spores as figured by 

 Massalongo {Goniocarpon ochraceum Ric. Lich. p. 47, f. 83) have the 

 upper cell largest, as in A. gregaria ; in the specimen from Glencar 

 they correspond with Massalongo's figure, and measure 0,015-17 mm. 

 long and 0,003-4 mm. thick. 



Hah. On trees. — Distr. Rare in Wales and S. Ireland. — B, M. 

 Glencar, Kerry. 



§ ii. EuARTHONiA A. Zahlbr. in Engler k Prantl Nat. 

 Pflanzenf. i. 1*, p. 90 (1903). 



Algal cells Trentepohlia. Apothecia blackish ; spores 1- or 

 more-septate. 



Spores \-septate. 



7. A. aspersella Leight. in Grevillea i. p. 60, t. 4, f. 4 (1872). 

 — Thallus in patches, effuse, pale yellowish. Apothecia very 

 minute, scattered, punctiform, linear, angular, sometimes con- 

 fluent, blackish-brown, hymenium K— ; spores obovate, colour- 

 less, 1-septate, 0,014 mm. long, 0,0055 mm. broad. — Leight. 

 Lich. Fl. ed. 3, p. 415. 



Somewhat similar to A. didyma, but differs in the darker-coloured, 

 angular apothecia, the somewhat smaller spores, and in the hymenial 

 reaction with potash. 



Hab. On holly. — Distr. Rare in Wales. — B. M. Capel Arthog, 

 Merioneth ; Gwydir Woods, Bettws-y-Coed and Trefriw, Carnarvon- 

 shire. 



8. A. g^alactites Duf. in Journ. Phys. Ixxxvii. p. 203 (1818). — 

 Thallus w^hite, thin, smooth. Apothecia small, dark-brown, 

 punctiform, round or oblong ; spores colourless, ovate-oblong, 

 1-septate, 0,012-14 mm. long, 0,004 mm. thick; hymenial 

 gelatine blue then sordid-wine-red with iodine.— y1. punctiformis 

 var. galactina (errore pro galactites) Ach. Lich. Univ. p. 141 

 (1810) ; Verrucaria galactites DC. Fl. Franc, v. p. 315 (1805). 



Distinguished by the white thallus. The spores are rather broad 

 above, the lower cell tapering downwards. 



Hab. On trees. — Distr. Rare in S. and N. England. — B. M. Tor- 

 quay, Devon ; Lymington, Hants ; Hatfield Peverel, Essex ; near 

 Ayton, Cleveland, Yorkshire. 



p 2 



