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best able to reckon them) are known as North American. — G. eulectra, 
Tuckerm. (Lich. Calif. p. 34) is distinguished by a stroma-like accessory 
exciple; and has only occurred in New England (Myself) and Illinois (Mr. 
E. Hall). Spores in eights; eruceeform; 12-15-locular; the length six 
to eight times exceeding the diameter ; colourless, or pale brownish. —— 
G. scripta (L.) Ach., occurs everywhere, at the North and South alike, 
in the common European forms, and passes into some states, especially 
southward, unknown to Europe.—Among these is the v. tenella (Graphis, 
Ach., Nyl. in Prodr. Fl. N. Gran. p. 73, & Herb. Lindig nu. 864) a readily 
observable, tropical lichen, which has been found in Texas (Mr. Wright) 
and appears ill-separable from the species. — The condition of G. scripta 
with wholly black, or entire exciple (G. assimilis, Nyl.) is perhaps less 
common than the dimidiate form, but occurs in New England, and at the 
South. Spores, in these forms, in eights, from ellipsoid becoming oblong, 
and eruceform, 6-10-locular, the length thrice to five times exceeding 
the diameter; colourless, orat length scarcely brownish. In the southern 
lichen the spores are now abbreviated and ellipsoid, and the flattened, 
approximated spore-cells need only to commence the next succeeding 
process, of division vertically, to introduce the v. analoga (G. analoga, 
Nyl.) which is to the form now immediately to follow exactly as G. assim- 
ilis, Nyl., to his G. scripta. —The v. sophistica (G. sophistica, Nyl.) is then 
the condition of the ordinary, dimidiate state of G. scripta, in which the 
spores reach the muriform stage; but though found in Europe, and 
tropical America, this has only very recently been observed here (southern 
Texas, Mr. Ravenel). The form differs from @(G. scripta) in nothing but 
the grade of evolution of the spores; and in the now diminished number 
of spores contained in the thekes (as to which compare Buellia oidalea, 
&c.,) and can be detected only by the microscope. Spores of our plant 
observed only in twos and fours; offering eight to twelve transverse series 
of spore-cells; 0,023-0,053™™- long, and 0,011-0,023™™- wide. ———G. elegans 
(Sm.) Ach., is distinguished from the last species by the thicker, furrowed 
margins of the exciple, and longer, often broader spores, and is almost 
confined, here, to the South (North Carolina, Rev. Dr. Curtis; South 
Carolina, Mr. Ravenel; Florida, Dr. Chapman; Alabama, Mr. Beaumont ; 
Louisiana, Hale; Texas, Mr. Ravenel) but has turned up also, like Biatora 
parvifolia, in New Jersey (Mr. Austin). The North American lichen (as 
also the tropical, as exhibited in Cuba) is commonly smaller and often 
slenderer than the European, but like that (Fr. L. £. p. 370) varies much 
as G.scripta. Sporesin eights; eruceform; 8-11-locular; the length five 
to seven times exceeding the diameter; colourless, or scarcely brownish. 
—The thalline margin is finally obscure in the European plant, and some- 
times quite disappearsin certain forms of the tropical ( Opegrapha striatula, 
Ach., e Nyl. Graphis, Nyl. O. rimulosa, Mont.) but these forms, though 
now greatly narrowed, and also elongated, so as to look rather like G. 
scripta, do not appear to be clearly distinguishable, in any wide view, by the 
