84 Rev. W. A. Leiglitou on the British Graphidese. 



works retains all under Opegrapha and Arthonia. Fee in the 

 first part of his ' Essai sur les Cryptogames ' (1824) divides the 

 Graphidece as follows : — " Arthonia, fausses lirelles sessiles, ho- 

 mogenes, immarginees, non impressionees ^^ = Arthonia, Ach. 

 L. Univ. " Heterographa, fausses lirelles sessiles, homogenes, 

 maculiformes en vieillissant, pourvues d'une fente dans la 

 jeunesse/' founded on Opegrapha faginea and quercina, DC. 

 [Opeg. macularis, Ach.), which is regarded by Fries as a fungus, 

 and perhaps justly. " Enterographa, lirelles profondement im- 

 mergees, homogenes, non impressionees/' founded on Opegrapha 

 crassa, DC. {Sagedia aggregafa, Fries). " Opegrapha, lirelles 

 sessiles, homogenes, impressionees " = Opegrapha, Ach. L. Univ. 

 " Graphis, lirelles sessiles, heterogenes, canaliculees " = Graphis, 

 Ach. L. Univ. " Sarcographa, lirelles labyrinthiformes h base 

 charnue.^' " Fissurina, fausses lirelles situees inferieurement, 

 determinant une fissure dans le thallus qui margine.^^ 



Eschweiler (Syst. Lich. 1824) makes nine genera out of Ope- 

 grapha, Graphis and Arthonia of Acharius, using the form and 

 structure of the lirella as the foundation of his arrangement ; viz. 



1. Diorygma, type Oj)eg. hieroglyphica, Pers. Act. Soc. Wetter. 



2. 16. t. 10. f. 3, "orbis novi incolse." 2. Leiorreuma, which 

 includes many tropical species of Graphis, Ach. As its type 

 Opegrapha LT/ellii, Eng. Bot. t. 1876. is given, but the section of 

 that plant which is represented with an entire perithecium sur- 

 rounding the base, as is really the case in the authentic spe- 

 cimens which 1 have examined in herb. Borrer., does not corre- 

 spond with the section of the same part in the figure of Leior- 

 reuma hepaticum given by Eschweiler, in which the perithecium 

 is lateral only in accordance with the generic description. 



3. Graphis =^ Graphis, Ach., according to the figures given, and 

 those of Acharius, ' Lich. Univ. ' (t. 3. figs. 14, 15) referred to. 



4. Opegrapha = Opegrapha, Ach., section 1. Hysterina, Ach. 



5. Oxystoma, type Op. cylindrica, lladd. Act. Soc. Ital. della Sci- 

 enza, xviii. 1820, tome iii. fig.l. 6. Scaphis= Opegrapha, Ach., 

 section 2. Alyxoria, Ach. 7. Lecanactis, type Arthonia lyncea, 

 Ach. 8, Sclerophyton, Eschw., " perithecio mere infero, nucleum 

 tenuem suflTulciente, disco planiusculo.^^ 9. Pyrochroa, types 

 Graphis coccinea, Holl. ; G. caribcea, Ach. — all tropical plants. 

 Eschweiler figures the sporidia of each genus, but in Fee's esti- 

 mation incorrectly. Fries in his ' Systema Orbis Vegetabilis ' 

 (1825)re-an'anges them in six genera: — 1. Graj)his=^ Leiorreuma, 

 Eschw. ; its type Graphis Afzelii, Ach. 2. Opegrapha in four 

 subgenera, viz. A. Hysterina= Opegrapha, Eschw., and Opegrapha 

 sect. Hysterina, Ach. B. Oxystoma, Eschw. C. Scaphis, Eschw., 

 and Opegrapha, sect. Alyxoria, Ach. D. Erumpentes= Graphis, 

 Eschw. £and by consequence Ch'aphis, Ach.]. 3. Lecanactis, 



