278 DUBLIN UNIVERSITY 



Stigmatiditjm (Mey.). 



1. S. crassum{Dub.). Sagedia aggregata (Fr. Leight. Br. Aug. Lich.) 

 On the rugged bark of trees ; common. 



2. S. Hutchinsice {Leight.). Platygramma Hutchinsice (Leight, Mon. 

 Br. Graph.). On shaded rocks, Dunscombe Wood, near Cork. This 

 plant was, as the name indicates, originally discovered by Miss Hut- 

 chins. 



Arthonia {Ach.). 



1. A. cinnabarina (Wattr.) Coniocarpon cinnabarium(D. C), (Leight, 

 Br. Graph.). Spiloma gregarium (T.et B.). Very common on trees. Va- 

 rious forms occur in which the apothecium ranges from nearly white, 

 through rose-colour and brick-red, to almost black. On holly, at 0' Sul- 

 livan's Cascade, Killarney, a var. {astroideum), is found with apothecia, 

 apparently lirella form, radiated. In all the states of this plant which 

 I have seen, the spores are precisely identical. 



2. A. lurida {Ach.). On young oak and Spanish chestnut, Castleber- 

 nard Park, Bandon. On Salix cinerea, by the lake at Luggelaw, Co. 

 Wicklow. 



3. A. astroidea {Ach.). (Leight. Br. Graph.). A vulgaris, B. astroidea 

 (Schcer. Lich. Heb. Exs. 16 ! 517 !). Common, especially on young oak. 



Var. Swartziana. A. Swartziana {Ach.), (Leight., Mon. Br. Graph. 

 Opegrapha atra, \. Swartziana (Schcer., Lich. Helv. Exs. 462 !). Abun- 

 dant on young ash and other trees. 



Var. epipasta. Arthonia epipasta (Leight.) Mon. Br. Graph., 

 (according to Nylander). On smooth bark of young trees, Great Island, 

 and Bostellan, Cork. 



In all our Irish forms the spores were exactly identical. Specimens 

 which I have seen of English growth {var. astroidea) had the spores 

 more regular in their outline, as represented in Leighton's figure"; but 

 this seems to depend on the age of the plant. 



4. A. ilicina {Tayl.), (Leight., Mon. Br. Graph.). On holly at Kil- 

 larney and Glengariff ; plentiful. A fine and distinct species. 



5. A. glaucomaria (Leight, Lich. Br. Exs. 2471). Parasitic on 

 the disk of the apothecia of Urceolaria scruposa ? At Barclay's Bock, 

 Co. Down ; Admiral Jones. 



6. A.punctella {Nyl.) {n. sp.) Parasitic on thallus of Lecidea albo- 

 atra {Saxicola) and Lecanora erysibe. On rocks exposed to the tide, below 



