(39) 
(v. membranacea, Nyl.) occurs here in California (Mr. Bolander) and may 
be taken for P. polydactyla.——P. polydactyla v. scutata, Fr. (Peltidea 
scutata, Borr.! Grev.! P. hymenina, Floerk.! P. horizontalis, v. hymenia, 
Moug. et Nestl. n. 541, pr. maz. p.) has occurred as yet rarely with me, 
and only barren. I possess, however, fertile specimens from trunks in 
Vancouver’s Island (Dr. Lyall in Herb. Hook.) and the lichen is readily 
distinguished from the type by its crisped, at length densely-sorediate 
margins, and from P. horizontalis by the spores. To the species last 
named, and by the same criterion, must be referred the P. polydactyla, v. 
scutata of Lich. Amer. exs.n. 11 (and also of Nyl. Syn. 1. ¢. pr. p.) which 
has indeed, considered in its full extent, the whole habit of P. horizon- 
talis; and is, according to Dr. Nylander (Lich. Scand.) Acharius’s v. 
lophyra of that species. 
Erioderma, Fée (Ess. p.145. Suppl. p.149. Mont. Diagn. Phyc.in Ann. 
3, 18, p. 309) is a tropical genus of few species, referred, so far as then known, 
to Sticta by Acharius, and to Peltigera by Fries, and included in their Pelti- 
gerei by both Fée and Montagne, but associated with Pannaria by 
Nylander. The latter affinity will not indeed be questioned here, where 
Pannaria is viewed as immediately contiguous to the Peltigerei; but 
Erioderma possesses some features which should seem distinctively 
Peltigerine. The whole habit of the upper side of the thallus in the best 
developed form (#. Wrightii, Tuckerm. Suppl. 1, and in Wright Lich. 
Cub. n. 109) is quite that of Peltigera; nor do I know with what else to 
compare the under side of EZ. wnguigerum (Bor.) Nyl. (Peltidea glauces- 
cens, Tayl.). This side is less prominently veined or nerved in £. Chilense, 
Mont. (Valdiv., Lechler!) and, in the otherwise not dissimilar E. polycar- 
pum, Fée (Cuba, Wright!) is besprinkled with tufts of black fibrils, pass- 
ing, in #. Wrightii, into a dense, spongy cushion, well-comparable with- 
out doubt, to that of some Pannarie, but yet not unexampled, as we 
have seen above, in Peltigera. The (marginal) apothecia are, as respects 
all external characters, similar to those of Sticta; but often terminate 
slightly produced lobules, one of the most characteristical notes of Pel- 
tigera. Itis finally not perhaps without interest that the ovoid or ellip- 
soid, at length somewhat fusiform, simple spores, which shew the same 
indications of coloration noted already in the other Peltigerine genera, 
are often well comparable with young (simple) spores of Solorina crocea. 
Andif I donot wholly mistake, there are not wanting other indications, — 
as in the breaking up of the spore-mass (sporoblast, Koerb.) when the 
spore becomes now distantly suggestive of that of Lecanactis premnea — 
of a still nearer relation to Peltigera and Sticta. 
XVII.—SOLORINA, Ach. 
Ach. L. U. p. 27; Syn. p. 8. Eschw. Syst. p. 21. Mont. Apercu Morph. 
p. 11. Tuckerm. Syn. N. Eng. p. 20. Scher. Enum. p. 22. Norm. 
Con. p. 14, t. 1, f. 7,6. Tul. Mém. Lich. p.19. Mass. Mem. p. 25, 
