(212) 
Well distinguished as they appear, for the most part, in habit, Glyphis 
and Chiodecton make no uncertain approaches to each other (as G. laby- 
vinthica to C. seriale) and their distinction may be said to be largely 
determined by the spores; Chiodecton being comparable in this respect 
with Opegrapha, as Glyphis, most evidently with Graphis. 
With the genus last named the connection of both groups must, in 
view of what is now known of them, be called intimate. Jedusula of 
Eschweiler and others—based upon a demonstrable aberration of the 
stellate groups of apothecia in Graphis dendritica, &c., in which, finally, 
by the confluence of the crowded proper exciples, an irregular, macule- 
form apothecium, as, often, by that of the thalline exciples, a stroma? is 
produced, —is, at first sight, scarcely less distinct than Glyphis ; and 
certain lichens may be said to be still in question between the two. Per- 
haps no one, familiar, in a measure, with these groups, can attentively 
examine the fine set of specimens given in Lindig Herb. Nov. Gran., to 
illustrate Graphis tricosa, Ach., and G. intricans, Nyl., and Glyphis 
medusulina and G. actinobola, Nyl., without the decided impression that 
we have here, at one end of a most intimately related series of forms, a 
Graphis, of the group represented by G. dendritica, and at the other so 
close an approximation to Glyphis labyrinthica that we may well incline, 
with the learned lichenographer to whem we owe the elucidation of these 
lichens, to regardit as touching the last-cited Glyphis. But Glyphis actino- 
bola (as in Lindig n. 2656) appears inseparable from Graphis intricans (as in 
n. 2579 of the same collection) by any difference beside the unsatisfactory 
one assumable from the blackening hypothecium; and the lichen last 
named (as in Lindig n. 2610) differs scarcely at all from G. tricosa (Lindig, 
2, n. 148) except only in the rather smaller spores. And Chiodecton, 
though so marked in type (C. spherale and C. myrticola) as scarcely to be 
comparable with other groups of Graphidacei, beside Glyphis, unless with 
some forms of Platygrapha and Enterographa, passes notwithstanding 
into extreme states (as compare the large series of specimens of C. per- 
plexum, Nyl., in Lindig Herb. N. Gran., especially n. 2577) not distantly 
suggesting similarly extreme conditions of Graphis dendritica v. medusula. 
With the last indeed—the type of Jledusula, Eschw.,—Fries, as we 
have seen above, though far from implicitly accepting its generical separa- 
tion, significantly associated both Chiodecton and Glyphis, in his Glyphidei. 
LIIL—CHIODECTON, Ach. 
Ach. Syn. p. 108; in Linn. Trans. 12, p. 43. Eschw. Syst. p. 19; Lich. 
Bras. l. c. p. 168. Fée Ess. p. 38, 62, t. 1, f. 17, & tt. 17,18; Monogr. 
Gen. Chiod. in Ann. Sci. 17; Suppl. p. 49, t. 40. Fr. 8.0. V. p. 271; 
1 “« Hoe enim, typice ut loquar, tantum ex apotheciis confertioribus oritur’ Fr. 
S. 0. F. p. 270. 
