102 LICHENES. [Thelotrema. 



1. P. pertusa, ACH. Thallus cartilagineo-membranaceous, 

 grey, smooth ; the warts of the apothecia crowded, subglobose, 

 with many dark, depressed points. Ach. Lick. Un. p. 308. 

 Eng. Bot. t. 677. 



Near Belfast, Mr. Templeton. In Askew Wood, County of 

 Kerry. Thallus very thin towards the edge, which is whiter : by 

 moisture it becomes somewhat gelatinous and semitransparent. The 

 orifice or pore of the apothecia is dark brown or black, beneath which 

 the nucleus, of a pale brownish flesh colour, is elongato-ovate, deeply 

 immersed. The internal structure of the nucleus noticed by Acharius 

 is remarkable, for among a mass of pellucid filiform and punctiform 

 bodies occur a few others oblong, very wide, and with double tegu- 

 ments, 



2. P. ceuthocarpa, HOOK. Thallus tartareous, continued, 

 cream-coloured, tessellated, unequal, smooth, border dark-olive, 

 zonate; warts of the apothecia tumid, globose, smooth, with 

 black, depressed points. Hook. Eng. Flor. v. 5, p. 160. Eng. 

 Bot. t. 2372. Isidium microsticticum. Turn, and JSorr. Lich. 

 Brit. p. 94. 



On slate rocks, near Bantry, Miss Hutchins. Sir Thomas Gage. 

 South of Ireland ; not uncommon. 



3. P. fallax, ACH. Thallus cartilagineo-tartareous, rugose, 

 grey, or greenish -grey ; warts of the apothecia crowded, irre- 

 gular ; pores large, oblong, distorted, bordered, blackish. Ach. 

 Syn. p. 110. Lich. Un. p. 310. 



On old trees near Belfast, Mr. Templeton. Askew Wood, County 

 of Kerry: also on rocks, Dunkerron Mountain. The wide, cylin- 

 drical, opaque vessels, with their pellucid coats, among the fibres and 

 granules of the nucleus are very remarkable. 



4. P. isidioides. " Thallus thick, tartareous, frustuloso-areolate 

 yellowish-brown; apothecia small, globose, pale, immersed in 

 tumid, roundish warts, except the darker, slightly prominent 

 apex." Verrucaria isidioides., Borr. in Eng. Bot. Supp. t. 2622, 

 /. 1. Pertusaria isidioides, Hook. Eng. Flor. v. 5, p. 160. 



Rocks at Glengariff, near Bantry, Miss Hutchins. This is given 

 on the authority of Mr. Borrer. I have never seen it. Can it be a 

 state of Pertusaria ceuthocarpa ? 



16. THELOTREMA, Ach. 



Thallus cartilaginous, membranaceous, or subcrustaceous ; apo- 

 thecia verruciform, formed of the thallus, hollowed, margin- 

 ated, containing a nucleus within a membranaceous perithe- 

 cium, beneath a coloured disk. 



1. T. lepadinum, ACH. Thallus cartilagineo-membrana- 

 ceous, whitish or glaucous-green; warts of the apothecia subco- 

 nical, their margin inflexed, perithecium membranaceous ; disk 

 pruinose, flesh-coloured or dark brown. Ach. L. Un. p. 312. 

 Eng. Bot. t. 678. 



