96 Tuckerman’s Enumeration of 
fertile with us ; and I have found a single specimen of a plant 
resembling the third species more than either of the other 
two; more specimens are however needed to determine it. 
SırnuLa, the other genus of this tribe, is represented in the 
European district by a single species, peculiar as yet to the 
extreme. northern parts of the Scandinavian peninsula. 
Belonging to the next tribe ENDOCARPE 4, Scotland and 
Sweden possess four genera, three of which occur in our region. 
Of four species of Enpocarpon found in the European district, 
although three of them are common New England plants, 
only one, and that the least conspicuous, has occurred to me 
at the Mountains. Of Prrrusaria, represented abroad by 
five species, I can only reckon two. Of TugrornEa there is 
buta single species in Sweden and Scotland: we have this, 
and another, peculiar to our own Flora.. . 
Of the tribe VERRUCARIE.£, there are 2 genera in the for 
eign region ; we have one of them. Srcesrria has 2 species, 
both unknown here. Verrucaria has 15 species, of which 
we have 5, and also one peculiar to our Flora. 
The last tribe is LIMBORIEZ, containing 4 genera, which 
exhibit the lowest developments of lichenose vegetation, and 
a near approach to a fungoid character; so much so that one 
genus may be said to hang between Lichenes and Fungi— 
and several species have been referred to both Orders by 
botanists.. Four species of these Genera belong to the Euro- 
pean district referred to. I have as yet detected neither of 
them here. 
Several genera remain to be noticed, asks to de 
Order BYSSACEJE. As constituted by Fries, this Order in- 
cludes Nostoc, Cenogonium, Ephebe, Collema, &c., which 
differ from Lichenes in their homogeneous structure ; and are 
analogous to the Ulvaces, just as true Lichenes may be 
to be to the Fucaceæ. Of this Order three genera, ‘coma 
referred to the Lichenes, are found in Scotland and Sweden, 
. and also occur in our region. These are CoLLEMA, Lzrr0- 
(€x, and: Eruese. The whole number of species. that T 
