262 



L1CIIENACBI. 



[PARMELIA. 



n. 1513. Parmtlia terelrata (Hoffrn.), Mudd, Man. p. 97. PtmneUa 

 diatrypa Hook. Fl. Scot. ii. p. 56 ; Sm. Eng. Fl. v. p. 204 ; Tayl. 

 in Mack. Fl. Hib. ii. p. 150. Physcia diatrypa Gray, Nat. AIT. 

 i. p. 436. Lichen diatrypus Sm. Eng. Bot. t. 1248. Brit. Exs. : 

 Leight. n. 264 ; Larb. Caesar, n. 66 ; Cromb. n. 145. 



In general appearance like small states of P. physodes, from which, 

 apart from the chemical reaction of the medulla and the number of the 

 spores, the peculiar perforations in the lacinise at once distinguish it. 

 The thallus is usually sprinkled with round whitish soredia (form 

 sorediobola Nyl.). In this country it has not occurred fertile. The sper- 

 mogones, which are very seldom present in our specimens, are as in 

 P. physodes. 



Hob. On rocks among mosses and on the trunks of trees in maritime 

 and upland districts. Distr. Local in the Channel Islands, S.AV. Eng- 

 land, N. Wales, S. Scotland and the W. Highlands, in S.W. and N. 

 Ireland. B. M. : Bonne Nuit, Island of Jersey. New Forest, Hants: 

 Bolt Head and Valley of Rocks, Lynton, Devonshire ; near Penzance and 

 Tregawn, Cornwall ;' Barmonth and Dolgelly, Merionethshire ; foot of 

 Snowdon, Carnarvonshire. New Galloway, Kirkcudbrightshire; Bal- 

 lachulish, Argyleshire. Pass of Keim-an-Eigh, co. Cork ; Glenmore Lake 

 and Dunkerron, co. Kerry ; Connemara, co. Galway ; Cushendun, co. 

 Antrim. 



43. PARMELIOPSIS Nyl. 

 Lich. Scand. ( 1861) p. 105 (ut 

 sectio Parmeliae) ; Not. Siillsk. 

 pro F. et Fl. Fenn. Forh. 

 n. ser. v. (1866) p. 121. 

 Thallus small, thin, appressed, 

 stellate ; beneath sparingly 

 fibrilloso-rhizinose. Apothe- 

 cia small, parmelioid ; para- 

 physes not discrete ; spores 

 8nae, simple, more or less 

 ellipsoid, colourless ; hy me- 

 nial gelatine bluish with 

 iodine. Spermogones scat- 

 tered, at length slightly pro- 

 minent ; sterigmata short, 

 simple ; sperm atia long, aei- 

 cular, arcuate. 



A small genus separated from 

 Parmelia on account of its 

 spermatia, which are like those 

 of Squamaria in the Lecanorei, 

 but the thalius shows that it 

 belongs to this tribe. Two of 

 its three European species occur 

 sparingly in Great Britain. 



we s. SB. 



.Fig. 45. 



Parmeliopsis ambigua Nyl. . Vertical 

 section of a young portion of thallus, 

 with a rhutna beneath, x200. b. Ver- 

 tical section of an apothecium, x30. c. 

 A theca, X350. d. Spores. X500. e. 

 Vertical section of tliallus with a spermo- 

 gone (on the left beneath, a rhizina), 

 X30. /. Steriginataandsperrnatia, X500. 



