(4) 
rus. Thamnolia (Ach.) Scher., associated with Siphula by Nylander, as 
by other recent writers, and indeed by Wahlenberg, and Acharius, is 
howerer, at any rate, Cladoniine. 
I.—ROCCELLA, DC. 
Ach. L. U. p. 81; Syn. p. 243. Eschw. Syst. p. 23. Fr. 8. 0. Y. p. 237; 
L. E. p. 33. De Not. Framm. Lich. p. 47. Tul. Mem. sur les Lich. 
p. 173. Norm. Conatus redact. nov. Lich. p. 13. Mass. Mem. p. 68. 
Nyl. Syn. 1, p. 257, t. 8, f. 2-5. Schwend. Untersuch. tib. d. Flech- 
tenth. in Naeg. Beitr. 2, p. 165, t. 6, f. 2-17. Th. Fr. Gen. p. 50. 
Parmelize sect., Mey., Wallr. Everniz sp., Eschw. in Mart. Fl. Bras. 1, 
p. 219. Roccella sect. B, Stizenb. Beitr. z. Flechtensyst. in Bericht. tib. 
d. St. Gall. Gesellsch. 1861, p. 175. 
Apothecia scutelleformia, lateralia, disco nigricante, hypothecio 
nigro. Spore dactyloideo-fusiformes, quadriloculares, incolores. 
Spermatia acicularia, arcuata; sterigmatibus sub-simplicibus. Thal- 
lus fruticulosus dein pendulus, cartilagineo-coriaceus, intus stuppeus. 
Maritime rock-lichens of the warmer regions of the earth, reaching 
northward as far as the southern coasts of England; nearly related 
(afines) to Ramalina ; and more remotely (analog?) to Sticta and Dirina ; 
as also, in other tribes, to Stereocaulon, Platygrapha, and Chiodecton. 
The type, whether we regard habit, or anatomical characters (upon 
which compare especially Schwendener, 1. ¢.) is a remarkably distinct 
one; but the species, even after Nylander’s revision, are by no means 
well-defined. It is in fact still questionable, whether R. fuciformis 
(Lichen fuciformis, L.) is properly to be separated from R. tinctoria 
(Lichen Roccella, L.) and, in this view, Wallroth’s reduction of all the 
forms known to Acharius to a single species, in which he is followed by 
Eschweiler (Bras.) will appear less strange. The Roccelle are found 
also, but more rarely, on trees; and our own form, R. lewcophea, Tuck- 
erm. Suppl. 1 (Amer. Journ. Sci. 25) p. 423, from the coast of California, — 
nearest without doubt to the South American R. intricata, Mont., and 
related through that to &. tinctoria—has only occurred as yet on the 
shrub (Obione) upon which it was discovered. 
Nylander points out the often curious variations of the apothecia of 
Roccella, suggesting now Platygrapha, and now even simulating Lecidea; 
it is impossible, however, to question that their type is scutelleform. Of 
the six species reckoned in the Synopsis of the author last cited, three 
are inhabitants of Europe, and all but one of South America. <A sterile 
Roccella, with the aspect of 2. phycopsis (Ny). in Prodr. Fl. N. Gran. p. 12) 
was found by Mr. Wright in Cuba; and reference has been made else- 
where (Syn. Lich. N. Eng. p. 13) to similar specimens seen by the writer 
in the British Museum, the collection of which they were part purporting 
to be made ‘‘in Carolina, Bermudas, and the Caribbees.” 
