1892] Comparison of the Hepatic Floras. 307 
As most of this paper is necessarily statistical, we present 
only some of the leading features of a detailed study of the 
three floras: — 
1. Ofthe 214 boreal and sub-boreal species, eighty per 
cent. are European, seventy-six percent. are American, and 
forty-six per cent. are Asiatic. While the larger part of the 
species of Europe and America have been brought to light, it 
is quite likely that the smaller number known from the more 
extensive Asiatic continent is due to the limited exploration 
of that region. 
The distribution by orders can be seen as follows:— 
¢ £¢ Ss oe } 4 g 
BS “5 <a ae % Hy} zw 
85 Bs 8 84 a 8 g 
EE EY Et ay < < 
s #4 Eg FE te > > 
8 oe Se 30 8s 9g v ed 
o Sart a 5 ees = i 
a eat on) Os o 
ond ond on g ne xO PA 
z Bes e ple | a a 
4; 6.3 ie 405 I I = 
hanti hes enn foal Cie I = 
Anthocerotacee,  - . viele =. Pe sa - ~ 
ermaniacee, 56 .. 112 . FO: ck RSS 24 32 10 
Totals . . . 67 129 85 69 26 34 es 
Further percentages will appear in the following:— 
Per cent. of 
Number. all boreal 
. species. 
gitcumpolar EEL Ge al nie eaters le a ag are 3 RTO I 
sey Common to Europeand America . =... - . ++ 49 
2A common to Europe andAsia . . .... - - 385 39 
mE it €s common to Asiaand America . . . +. - + + 99 32 
“ of rope las OAM Caper Lye st We RAN La ED 26 12 
is s Ot Aierita ys 50= yes ere yee bee eae 15 
Of Asia. 33, =: 10 4 
sleet Of the 163 American species, 129 or seventy-eight per 
whil are of the European flora; sixty-nine are also Asiatic, 
Ne thirty-two or twenty per cent. are endemic. 
diets : f the ninety-eight Asiatic species, eighty-five (or 
cent y SIX per cent.) are European, while only ten (ten per 
-) are endemic. 
peo the 173 European species only twenty-six, or fifteen 
Per cent. are endemic, and this number is likely to be reduced 
Eu rey sp 
eos, and Asia. The percentage of these circumpolar spe- 
vatles among the orders; while only 30 per cent. of the 
