ARTHOPYRENIa] PYRENULACEiE 317 



(noil V. stigmatella var. lactea Ach. tide Muell.-Arg. in Flora 

 Ixviii. p. 259 (1885)). 

 Exsicc. Mudd n. 294. 



The perithecia are slightly more spreading at the base than in 

 the species, in this character approaching A, analepta. 



Hah. On the bark of trees, chiefly s^-camore. —Distr. Rare in 

 N. England. — B. M. Kildale, Cleveland, Yorkshire. 



2. A. punctiformis Arn. in Flora Ixviii. p. 160 (1885). — - 

 Thallus developed below the bark, forming dark patches, or the 

 bark remaining unchanged. Perithecia minute, black, shining, 

 convex or somewhat conical, semi-immersed or becoming almost 

 superficial ; perithecial wall dimidiate ; asci small, pyriform or 

 usually angular at the base with the stalk-cell at one side ; 

 usually 0,040-60 mm. long, 0,014 mm. thick, sometimes more 

 swollen ; paraphyses indistinct, mostly obsolete ; spores oblong 

 or oblong-ovoid, 1-septate, the cells almost equal, 0,014-17 mm. 

 long, 0,003-5 mm. thick. — A. epidermidis var. punctiformis Mudd 

 Man. p. 305 (1861) ; var. atomaria Mudd /. c. Verrucaria 

 punctiformis Pers. in Ust. Ann. Bot. xi. p. 19 (1794) fide Arn. 

 L c. ; Hook, in Sm. Engl. Fl. v. p. 150 ; Tayl. in Mackay Fl. Hib. 

 ii. p. 88 ; Leight. Angioc. Lich. p. 41, t. 17, fig. 5 & Lich. Fl. 

 p. 433 ; ed. 3, p. 466 (excl. ff. tremul-ee and elongatula). V. epi- 

 dermidis var. punctiformis Nyl. Lich. Scand. p. 281 (1861) ; 

 Cromb. Lich. Brit. p. 19. Lichen punctiformis Ach. Lich. Suec. 

 Prodr. p. 18 (1798) ; Engl. Bot. t. 2412. L. atomarius Ach. tom. 

 cit. p. 16? Lejophlea punctiformis S. F. Gray Nat. Arr. i. p. 496 

 (1821). 



Exsicc. Mudd n. 298 ; Leight. nos. 288, 344. 



Differs from the preceding species in the smaller size of all the 

 parts and in the obsolete paraphyses. Leighton includes in f. divii- 

 nutula (var. deminutula Nyl. in Flora li. p. 164 (1868)) forms with 

 minute perithecia and larger spores, 0,016-22 mm. long, 0,003-4 mm. 

 thick, but the specimen of f. diminutula in the herbarium, collected 

 at the same time and place as Leighton's form (Tore Mt., Killarney), 

 does not differ from the species, the spores are somewhat elongate 

 and measure 0,017 mm. long, 0,003-4 mm. thick. 



Hah. On the bark of various trees. — Distr. Not uncommon through- 

 out the British Isles.— jB. M. Hurstpierpoint, Sussex ; Chedworth and 

 Chalford, Gloucestershire ; Bath, Somerset ; Hay Forest, Hereford- 

 shire ; Comberton Woods, Cambridgeshire ; Hoggart's Wood, Ingleby, 

 and Cliffrigg, Cleveland, Yorkshire ; Barcaldine, Lome, x^rgyll ; White 

 Point, Cork; Croghan, Cromaglown, Dinish, Tore Mt. and Derry- 

 currihy, Killarney and Glencar, Kerry ; Dublin. 



3. A. pyrenastrella Oliv. Exp. Syst. Lich. ii. p. 266 (1900). — 

 Thallus greyish or brownish, effuse, often indistinct. Perithecia 

 black, minute, semi-immersed, roundish, solitary or in small 

 groups confluent at the base ; perithecial wall dimidiate ; para- 

 physes indistinct, breaking up and disappearing ; asci cylindrical 



