(197 ) 
zoidea, Ach., is seen to be referable (as by Nyl. in Prodr. Fl. N. Gran.) 
to the group typified by G. dendritica. Several members of this last 
group have passed for Lecanactis of authors; and it is not without 
interest possibly that two species of Melaspilea have suggested to lichenists 
the same relationship. The exciple of the latter separates it from the 
Arthoniei. 
Two species are known to occur within our limits. MM. arthonioides 
(Fée) Nyl., has been found by me, on trunks, in swamps, in Hadley, Mass., 
and presents the aspect, as compared with our northern lichens, of a 
Lecidea, or Buellia; or,—the crust being mostly obsolete— of a similar 
Fungus. —— M. angulosa, Nyl. (Lecanactidis sp. nov., Tuck. in litt.) 
resembles on the contrary a Graphis of the dendritica-group; and has 
occurred in Texas (Mr. Wright) as also in Brazil (Nyl.). 
Fam. 2.—OPEGRAPHEI, Stizenb. 
Apothecia lirellaformia, rarissime rotundato-difformia. 
Two interesting types of this well-characterized and (in the tropics) 
most largely developed centre of the tribe are, as above indicated, want- 
ing with us. One of these,—Enterographa, Fée (Stigmatidium, Mey., 
prop. Nyl.)—belonging it should seem to the, in this tribe, sparingly 
represented colourless series, and resembling now Chiodecton, and now 
some lirellate Arthonia, not remote from A. rubella, may well have been 
overlooked; as several species occur in Europe, and others in the West 
Indies, and in Japan.—— The other, —Lithographa, Nyl. Prodr. p. 195 — 
is entirely extra-tropical, and distinguished not only by its simple spores, 
and the areolate thallus of some of its forms (Placographa, Th. Fr. 
Haplographa, Anz.) but as affording also the only examples that we have 
(Nyl. l.c.p.147. Anz. Catal. Sondr. p. 97) of myriosporous Graphidacet. 
XLIX.—OPEGRAPHA, (Humb.) Ach., Nyl. 
Opegrapha, Humb. Fl. Frib. Pers. in Ust. Ann. Bot. Ach. L. U. p. 43, 
pro max. p.; Syn. p. 70, pro p. Scher. Spicil. p. 45, pr.p. Fée Ess. 
p. 24, pr. p.; Suppl. p. 18, pr. p. Fr. 8. O. V. p. 273, pr. p.; L. E. 
p. 361, pr. p. Borr. in Hook. Br. Fl. 2, p. 143, pr. p. Mont. Pl. Cell. 
Cub. p. 180, pr. p.; Crypt. Guy. p. 33, pr. p.; Syll. p. 348, pr.p. Nyl. 
Enum. Gen. 1. c. p. 131, pro max. p.; Prodr. Gall. p. 151, pro max. p.; 
Lich. exot.1.c.; Prodr. Fl. N. Gran. p. 90; Syn. Lich. N. Caled. 
p. 54. Opegrapha pr. p., Oxystoma, & Scaphis, Eschw. Syst. p. 14. 
Graphis pr. p., Mey. Nebenst. p. 330. Eschw. Lich. Bras. p. 81. 
Opegrapha, Norm. Con. p. 25, t. 2, f. 18,1.c. Opegrapha pr. p., & 
