(198 ) 
Encephalographa, Massal. Mem. p. 101; Geneac. p.13. Anz. Catal. 
Sondr. p. 94. Th. Fr. Gen. p. 95. Opegrapha, Zwackhia, & Ence- 
phalographa, Koerb. Parerg. p. 248, &c. Opegrapha, Melanospora, 
& Stictographa, Mudd Man. Brit. Lich. p. 226. Opegraphe sect., & 
Encephalographa, Stizenb. Beitr. 1. c. p. 153. 
Apothecia lirelleeformia (rarius rotundata) subsimplicia, plerumque 
superficialia, excipulo proprio fere semper integre nigro. Spore 
parvule, ex ellipsoideo dactyloidez 1. seepius fusiformes, bi-quadri- 
pluriloculares, fuscescentes 1. decolores. Spermatia oblonga 1. bacil- 
laria; sterigmatibus simplicibus. Thallus crustaceus, uniformis 1. 
seepe hrpophleodes. 
The indications of natural habit which suggested the discrimination 
of Graphis from Opegrapha, are still instructive ; and in the tropical 
species of the group before us (as this group is recognized by Nylander, 
following here, it should seem, the conception of Acharius, as best expressed 
in the Lichenographia) no less than in those of the northern hemisphere. 
The present genus is, for the most part, readily distinguished from Graphis 
by its superficial, subsimple, always black apothecia, deprived wholly of 
thalline or thalloidmargin; but the value of even the last of these differences 
has been variously estimated by authors,—neither Fries, nor Eschweiler, in 
his latest work, according it more than subordinate importance —and the 
rest are clearly of small account. It might indeed at first appear that 
the smaller, dactyloid, or at length slenderly fusiform spores (leaning, 
says Koerber, towards the Lecanactis-type) differed also from those of 
Graphis in being referable—as were perhaps the less surprising ina 
group so largely northern—to the colourless spore-series ; and it is cer- 
tainly true that, in the greater proportion of forms, perfect spores are 
commonly colourless, and in some possibly always so. There is yet 
another presumption, looking the other way. In those tribes of Lichens 
which approach nearest to Fungi the proportional exhibition of the 
coloured type is vastly increased; and in Graphidacei this isas more than 
four to one. Nor are indications of colour wanting in several forms (as 
0. varia, O. involuta, O. microsema, Nyl.) while in the little group of 
species (Nyl. in. Prodr. Fl. N. Gran. p.92) represented by O. lentiginosa, 
and O. diplasiospora, Nyl.,— certainly Opegraphe, in spite of the vacil- 
lating characters of the hypothecium, in everything else—as well as in 
that represented by O. cerebrina, we find typically brown spores, well 
assumable as the key to the position of the whole genus; the anomalies 
of which, in this respect, are paralleled, not only in Graphis, but other 
natural groups (as Thelotrema, and Heterothecium) of the coloured series. 
According to the views maintained here, unilocular spores, which might 
also, and even probably, so far as analogy appears, be colourless, should 
be by no means impossible within the limits of the present natural group; 
