(49 ) 
(Mont.) Nyl.,as P. rubiginosa (known only in lecanorine forms) to P. tryp- 
tophylla. And, as an extreme member of the same assemblage, associ- 
able perhaps structurally with P. rubiginosa through P. fulvescens, must 
be reckoned, if referred at all to the present genus, the remarkably retro- 
grade P. lurida, Nyl. (Collema, Mont.) a not uncommon North American 
lichen, extending also to Japan (Wright) and the tropics; and combining, 
with often the exact habit of P. rubiginosa, an amount of deviation in 
thalline structure, from the latter, which can only be fully characterized 
as Collemaceous. The view to be here taken of the position of the Col- 
lemei, as in fact immediately contiguous to the Pannariei, removes the 
difficulty of attempting to conceive of such intimate relationship in plants 
of different orders, but it may still be questioned whether P. lurida 
should not follow P. swb-lurida, Nyl. (in Ann. ; Syn. Lich. N. Caled. 
p. 5) into a still closer association with the group represented by Collema 
byrsaum (Physma, Mass. Neag. p. 6; Dichodiwm, Nyl. 1. c¢.) the group 
being understood as properly intermediate between Pannarici and Col- 
lemei, but referable rather to the latter. —— P. rubiginosa is found, not 
very uncommonly, throughout New England, and extends southward to 
South Carolina (Ravenel). In this species the degradation of the folia- 
ceous thallus into the squamulose is at length most obvious; and if there 
were any doubt of its close relation to P. tryptophylla, none can well be 
entertained of the analogous affinity of P. pannosa to P. nigro-cincta.— 
The species last named (P. nigro-cincta (Mont.) Nyl.) has occurred, on 
trunks, in the low country of South Carolina (Ravenel) and Louisiana 
(Hale) ; the specimens agreeing generally with one of the New Granada 
ones (Nyl. in Lindig. n. 818) but by no means so well marked as the 
others, or as one received from Montagne; and might almost be referred 
to the next. Even the Cuban Lichen (Wright Lich. Cub. n. 103) in some 
of its states at least, is ambiguous; and suggests readily the finest forms 
(as Fellm. Lich. Arct.n. 98) of the northern plant (P. tryptophylla). But 
the best forms of P. nigro-cincta suggest unmistakably P. pannosa.m—P. 
tryptophylla (Ach.) Mass., occurs on trunks, and also, growing over mosses, 
on stones, in the mountains of New England, and in New York. Massachu- 
setts (H. Willey). Vermont (C. C. Frost). The near affinity of this species 
to those immediately preceding, will hardly be disputed; but it stands 
also, in some of its states (and similar difficulties are not unknown elsewhere 
in Pannaria) in apparently close relations to another group (Lecothecium, 
etc., Azctt.) which we find ourselves compelled, inthe present arrangement, 
to remove far from it. ——P. Hookeri (Sm.) Th. Fr., of the Scottish and 
Scandinavian mountains, has occurred in Greenland, Vahl. (Th. Fr. Lich. 
Arct.) but the still more interesting P. eleina (Wahl.) Nyl., which Dr. 
Fries takes for intermediate between P. rubiginosa and P. Hookert, is un- 
known as North American.—P. microphylla (Sw.) Del. (e Dub. 1. c.) 
is as frequent probably in the northern States as P. leucosticta ; and I 
possess it also from Ohio (Lesquereux) California (Bolander) and New 
7 
