THE CEYPTOGAMIC FLORA OF KENT. 337 



The stone on which this s^Decimen was found appeared to be 

 one of those boulders belonging to a different geological formation 

 which are here and there found scattered over the chalk in this 

 district, particularly near Maidstone, and are supposed to have 

 been deposited here by former glacial action. 



Placodium murorum {Hoffm.) 



On walls, rocks, &c. ; common. 



Bexley; Sevenoaks; Boro' Green; Brastead; Penshurst; Wye; 

 Hythe ; Sandgate. 



P. DECIPIENS, Am. 



On old walls ; frequent in Kent. 



Abundant on the walls of Eynsford Castle ; wall near Boro' 



Green ; Shoreham ; Brastead. 

 Known from the last by its paler colour and scabrous thallus, 

 and the areolate centre of the thallus. 



P. CALLOPISMUM (Ach.) 



On rocks and walls ; less frequent than P. murorum. E. B. 



2157, upper figure. 

 On a bridge between Staplehurst and Boughton Monchelsea ; 



Bexley ; on walls, Brastead ; Hythe ; Sandgate. 

 Known from P. rnurorum by its brighter orange colour and 

 flattened appearance. 



P. CITRINUM (Ach.) 



On walls, rocks, &c. E. B. 1793. 

 Bexley ; Brastead. 



[P. candicans (Dicks.) and P. variahile (Pers.) should be looked 

 for on rocks near the sea about Sandgate. The former occurs 

 abundantly at Hastings in a somewhat similar situation.] 



Lecanoea vitellina, Ach. 



On rocks, walls, stones, trees, &c. E. B. 1792. 

 On trees on Tunbridge Wells Common; Jenner Fl. Tunhr. 

 Eusthall Common ; Wrotham ; Lydd. 

 Var. epixantha (Nyl.) On trees in Chilstone Park, near Lenham. 

 Known from L. epixantha (Ach.) and L. j)hlogina (Ach.) by its 

 numerous spores, some of which are usually 1 -septate. 



L. candelaria [Ach.) 



On trees, pales, &c. E. B. 1794. 



On trees on Tunbridge Wells Common bearing shields which 



are rare ; Jenner Fl. Tunhr. Willesboro' Lees in fruit ; 



Penshurst Park ; Shoreham ; Brastead. 



Very similar in appearance to Physcia jmrietina var. lychnea, 



but easily distinguished by solution of caustic potash which tinges 



the latter dark red, but does not affect L. candelaria. 



L. GLAUcocARPA, var. pruinosa [Sm.) 



On the mortar of walls, limestone rocks, &c. E. B. 2244. 

 Sandridge, near Sevenoaks. 



2x 



