278 FUNGI. 
European states in the number of species of the Discomycetes. 
The Phacidiacei are not confined to temperate regions, but are 
More rare elsewhere. Cordierites and Acroscyphus (?) are tro- 
pical genera, the former extending upwards far into the tem- 
perate zone, as Hysterium and Rhytisma descend into the tropics. 
Amongst the Spheriacei, Xylaria and Hypoxylon are well repre- 
sented in the tropics, such species as Xylaria hyporylon and 
Xylaria corniformis being widely diffused. In West Africa an 
American species of Hypoxylon is amongst the very few speci- 
mens that have ever reached ts from the Congo, whilst 
HI. concentricum and Ustulina vulgaris seem to be almost cosmo- 
politan. TZorrubia and Nectria extend into the tropics, but are 
more plentiful in temperate and sub-tropical countrics. Dothidea 
is well represented in the tropics, whilst of the species of 
Spheria proper, only the more prominent have probably been 
secured by collectors; hence the Superficiales section is better 
represented than the Olfectg,and the tropical representatives 
of foliicolous species are but few. Asterina, Micropellis, and 
Pemphidium are more sub-tropical than temperate forms. The 
Perisporiacei are represented almost everywhere; although 
species of Lrysiphe are confined to temperate regions, the genus 
Meliola occupies its place in warmer climes. Finally, the 
Tuberacei, which are subterranean in their habits, are limited 
in distribution, being confined to the temperate zone, never 
extending far into the cold, and but poorly represented out of 
Europe. One species of 2fylitta occurs in Australia, another 
in China, and another in the Neilgherries of India; the genus 
Paurocotylis is found in New Zealand and Ceylon. It is said 
that a species of Zuber is found in Himalayan regions, but in 
the United States, as well as in Northern Kurope, the Tuberacei 
are rare. 
The imperfect condition of our information concerning very 
many countries, even of those partially explored, must render 
any estimate or comparison of the floras of those countries most 
fragmentary and imperfect. Recently, the mycology of our own 
islands has been more closely investigated, and the result of 
many years’ application on the part of a few individuals has 
