(173) 
(Fée) and other instances: but the value of this note is questionable ; 
and the genus, as a whole, with only a few decided exceptions belonging 
to the last section, in which the ultimate, muriform configuration of the 
spore-type is reached (Lopadium) exhibits colourless spores. That these 
are not typically colourless, but rather decolorate, is yet as conceivable in 
the case of Lecidea grossa (Pers.) Nyl. (Catillaria, Auctt. Psorothecium, 
Mass. Hsam.) and other lichens, which Massalongo has, not without rea- 
son, associated with it, as in the case of Catillaria concreta, Koerb., in its 
confessedly difficult relations to some recognized forms of Buellia. 
It is here the place, in view of Lecidea grossa, to say again, with 
Fries, that even the most subtle characters must give place to undoubted 
affinity. To us it is impossible to question the continuity of the series of 
changes by which the pale hypothecium of Biatora rubella, a, is trans- 
formed into the finally black one which underlies the intensely black disk 
of a form, already above alluded to, of B. rabella, v. Schweinitzii ; and 
the latter, however Lecideine,— and it simulates as well, very closely, 
Lecidea grossa, —is none the less a Biatora. In B. atro-purpurea (Mass. 
Lecid. intermixta, Nyl.) which, passing through a succession of changes, 
in both external and internal coloration, similar to that of Biatora 
rubella, reaches at length, in like manner, a blackened state most readily 
comparable with Lecidea, we have a yet more interesting example of the 
same sort; as this species agrees also with Z. grossa in the structure of its 
spores. Nor is this denigration of the hypothecium any more strange to 
the genus before us; as, to take but a single instance, fully appears in 
“ Tecidea melanocarpa, Nyl. (Heterothecium sensu Flot.) . . . apothecia 
atra intus fere nigra (vel hymenio solum sectione cinerascente) hypothe- 
cium denigratum,” &c. (Nyl. Lich. exot. 1. c. p. 260) which, as described, 
is scarcely less Lecideine, though, at the same time, without doubt asso- 
ciable with the same cluster of species which includes Heteroth. tubercu- 
losum, than Lecidea grossa. 
Of the section with bilocular spores (Psorotheciwm, Mass.) no example 
has been found within the limits of the United States. 2. versicolor 
occurs in the island of Cuba (Wright Lich. Cub. n. 225) with H. leptochei- 
lum, and H. endochroma, both also given in Wright’s collection, and the 
Jast also in Mexico (Nyl.) H. Simodense (Lecidea, Tuck. Obs. Lich.) is a 
Japanese lichen. The last three of these species are distinguishable from 
the first by their much smaller spores, but they are closely related to each 
other and to that in every other respect. And the first is equally near to 
types of the next section (Bombyliospora, Massal.) which only differs from 
the present in the number of the spore-cells. 
H. (Bombyliospora) tuberculosum is the earliest described of a group 
of similar lichens, which, occurring throughout the intertropical regions, 
affords also one example in the milder districts of western, and the moun- 
tains of central Europe; and another not known beyond New England in 
America. The last two are easily distinguishable from each other, but 
