SÉANCE DU 22 OCTOBRE 1877. 319-xxHI 
Peridermium corticolum has larger peridia, which are more inflated, 
not compressed and containing pseudospores 0"",020-0"",024. 
Peridermium acicolum has compressed peridia and elongated pseudo- 
spores which are from 0"",032-0"",040 x 077,020. 
This appears to me sufficient grounds for maintaining the two species as 
distinet. The P. cerebrum Peck, a North American form, is nothing more 
than à condition of P. corticolum. 
Recently I received from the Himalayas of India several forms of Peri- 
dermium ; and amongst them P. acicolum of the typical form on Pinus 
Smithiana ; there was also another which externally resembled P. acico- 
lum, but with the spores of P. corticolum. This I have called P. orientale. 
Either this form uniies the other two, as an intermediate condition, or 
else the three must be accepted as distinct species. The form called 
P. orientale occurred on the leaves of Pinus australis, Pinus longifolia, 
and Pinus excelsa. 
The next illustration is taken from the genus Reæstelia. The common 
R. cornuta Tul. is widely known, but a very similar species sent to me as 
R. cornuta from North America, on the leaves of a species of Cratægus, is 
neither that species nor R. lacerata Tul., but, as I believe, quite a distinet 
species, which I have called Restelia hyalina. The peridia are smaller 
and more delicate, pointed at the apex, and dehiscing by à longitudinal 
fissure throughout nearly their entire length. The cells of the peridia are 
smaller, much more delicate and without striation. A comparison of the 
two forms is only necessary to establish their claims to a distinct nomen- 
clature. 
Finally the genus Æcidium will furnish-an example in the well known 
Æcidium Berberidis P. It need not be said that this is a very characte- 
ristic species, with the peridia very much elongated and clustered together 
on a thickened discolored spot. Many years ago Shuttleworth found near 
Berne in Switzerland an Æcidium growing on Berberis vulgaris, which 
he named ZEcidium graveolens. It is characterized as having a peculiar 
odour when fresh, the peridia are scattered over the leaf without any 
thiekened or discolored spots, they are also abbreviated, and the cells of 
the peridium, as well as the spores differ in size. These features seem to 
me to warrant the recognition of ZEcid. graveolens Shutt. In order that 
all these forms may be seen and studied at leisure by the mycologists of 
France, the specimens exhibited will be placed in the herbarium at the 
Jardin des plantes at the close of this meeting. ` 
Après cette communication faite en langue anglaise par M. Cooke, 
M. Howse donne lecture de la traduction suivante : 
