( 245 ) 
No such complexity of excipular structure appears however to be 
predicable of Pertusaria ; the type of which, as already suggested in 
another place, may be considered as simply a peculiar modification of the 
lecanoreine hypothecium, conditioned by the here dominant misus to 
become compound. 
Conformably with the view that the Verrucariaceous fruit is in fact 
analogous to that of Thelotrema, it isthe exterior covering of the former, 
however diminished, that is equivalent to the proper (exterior) exciple of 
the latter, and still to be called perithecitum ; while the interior envelope 
(tunic, Leight.) assuming especial importance in the types with included 
fruit, may be distinguished as amphithecium, the term used by Koerber, 
and sufficiently explained by him! (Syst. p. 320). Such use of the terms 
appears, on several accounts, preferable to their transposition; upon 
which compare Th. Fr. Lich. Arct. p. 252. 
But though reduced by the signal losses to which we have above 
referred to what is, for the most part, a heap of obscure forms, of a type 
so low that the larger part perhaps is on the verge of exclusion from the 
class, the present tribe is still dignified by a foliaceous family, and needs 
therefore but a (possible) fruticulose expression, to exhibit all the series 
of thalline development which distinguish Parmeliacei, Lecideacei, and 
Caliciaceit. And in this view, Graphidacei, which with all its surprising 
variety of modification, and mostly well-marked lichenose character, is 
still confined to the lowest type of thallus, might certainly seem as inferior, 
as, according to Eschweiler, it should be regarded, in the elongation (as 
compared with the concentrical figure which is characteristical in all the 
other tribes) of its fruit. 
Considered in the way of analogy, the foliaceous Verrucariacei (Endo- 
carpei) may be said to represent Umbilicaria and Pannaria ; passing, 
like both of these, into microphylline, and, like the last, into finally almost 
crustaceous forms. These foliaceous expressions excepted, it is so easy 
and natural to refer the whole remainder of the tribe to a single family 
(Verrucariei) that the bulk is, without hesitation, subsumed by Nylander 
under a single genus. This family affords however some apparently 
available grounds of further specification. We here distinguish, following 
most lichenographers, the types with coloured perithecia (sub-fam. 
Segestriei) regarding these as offering some other marked indications of 
superiority, and as analogous at once to Eulecanorei and to Biatoret. 
Compound apothecia and a peculiar thalloid receptacle (stroma) finding 
1 It is yet obvious, from the above, that we cannot adopt the expression that 
the amphithecium is to be called, without qualification, the analogue of the hypo- 
thecium in higher lichens (‘ das Analogon des Keimbodens (hypothecium) bet den 
gymnokarpischen Flechten,’ Koerb. 1. ¢.) this place belonging rather to the perithe- 
cium, as representing the most important hy pothecial layer ; while the amphithecium 
stands for a layer, everywhere of inferior value, and, in higher lichens, for the most 
part, unknown. 
