ACOTYLEDONS. LICHENS. Lecanorct. 47 



SECT. II. DISCOIDKI. Apothecia scutelliform, snlsessile, fur- 

 nished with a disk formed of a peculiar coloured substance, 

 and surrounded by a margin of a different colour arising 

 from the thallus. 



15. URCEOLARIA. 



Universal receptacle crtistaceous, spreading, plane, adnate, uni- 

 form. Partial receptacle scutelliform, its disk concave co- 

 loured immersed in the crust, its margin formed of the crust 

 and of the same colour. 



1. U. Acharii, crust with a rather decided edge smooth with 

 narrow cracks pale brick coloured, disk reddish the margin 

 tumid, Ac/i. Syn. Lich. p. 137. Lichen Acharii, E. B. 

 t. 1087. 



. cyrtapsis, crust bordered smooth tessellated reddish at length 

 white, apothecia becoming elevated with the disk rather con- 

 vex reddish brown reaching the margin of the crust. Lichen 

 punciatus, E. B. t. 450. 



HAB. Common on rocks in the Isle of Mull, also at Sheean Ferry, 

 Mr. Turner and Hook. /3. Rocks, Scotland, Dickson. 



16. LECANORA. 



Universal receptacle crustaceous, spreading, plane, adnate, uni- 

 form. Partial receptacle scutelliform, thick, sessile aiid ad- 

 nate ; disk plano-convex, its margin thickish, formed of the 

 crust and of the same colour, somewhat free. 



* Thallus adnate, uniform. 

 f Disk of the apothecia black, naked. 



1. L. atra, crust with a somewhat decided edge granulated and 

 cracked greyish white, disk of the apothecia plane at length 

 swelling and black, the margin free raised at length waved and 

 crenulate. Ach. Syn. Lich. p. 146. Lichen ater, Lightf. 

 p. 813. E.B.t.949. 



HAD. Common on the bark of trees, and on walls and rocks. 



2. L. oculata, crust glabrous papillose and branched white, apo- 

 thecia sessile scattered, disk slightly .concave black, margin 

 turnid. Ach. Syn. Lich. p. 148. Isidium oculatum, Lich. 

 Univ. p. 576. Lichen oculatus, E. B. t. 1833. Lichen dac- 

 tylitius, Wahl. Lapp. 



HAB. Rocks in Scotland, Mr. Dickson. On Ben Lawers, growing 

 upon moss and grass, Mr. Turner and Hook. 



ft Apothecia brown in the disk. 



3. L. sulfusca, crust cartilaginous smooth at length granulated 

 unequal white or greyish, disk of the apothecia plano-convex 

 brown or almost black, margin tumid entire at length waved 

 and crenate. Ach, Syn, Lich. p. 157. Lichen sulfuscus, 

 p. 813. 



