ANNIVERSARY ADDRESS OF THE PRESIDENT. CV 
or less proportion of bases in the constituent labradorite. Thus soda, 
potash and water form a notable part of the labradorite of the mela- 
phyres, while these bases diminish and even completely disappear as 
the rock approaches to greenstones, basalts and modern lavas. They 
are replaced by lime, which then becomes the dommant base. 
Besides these communications there have been others, also present- 
ing much interest, such as the observations of M. Martius on the 
mass of the Jungfrau, which M. Studer refers to gneiss, masses of 
limestone being included among it; the note of M. Boué, referring 
to a memoir of M. de Hauer on the Cephalopods of the shelly lime- 
stone of Bleiberg, Carinthia, wherein three stages of cephalopods, 
each characterized by its fossils, is considered to be distinguishable 
in the Alps; a notice by Desmoulin of fossils in flints, which he in- 
fers are the remains in the south-west of France of upper chalk, 
equivalent to that of Maéstricht, the softer parts of these beds having 
been removed by denudation ; a notice by M. Viquesnel on the chalk 
of Turkey; a note on the mode of occurrence of the sulphur in the 
Soufritre of Guadaloupe by M. Ch. Deville. We have also a note by 
M. Boué on pseudomorphism arising from the disappearance of cry- 
stals of rock-salt in rocks ; a notice and analysis of a hydrosilicate of 
alumina, found at Montmorillon (Vienne) by MM. Damour and Sal- 
vétat ; a note on the pisolitic limestone (of the Paris district) by 
M. Hebert; remarks by M. Paillette in illustration of notes on the 
mines in the south of Spain by M. Pernollet; reflections in favour 
of the hypothesis of the central heat of the earth, by M. d’Omalius 
d’ Halloy ; a note by M. von Buch on some points connected with 
the structure of Terebratule, and on the range of nummulitic lime- 
stones ; a description of a gigantic Orthoceratite, six English feet long, 
from North America, by M. de Verneuil; a notice of the occurrence 
of a cretaceous Terebratula in some tertiary marls near Corbiéres, 
these marls considered equivalent with others full of cretaceous fos- 
sils in the Haute Garonne and Haute Pyrenées, by M. Leymerie. 
There are other notices and papers by M. de Collegno on the classi- 
fication of certain rocks in Italy ; on some peculiarities in the exte- 
rior form of the ancient moraines of the Vosges, by M. Collomb; on 
the genus Palzotherium, by M. Pomel; a notice of the rocks in the 
basin of the Adour, by M. Delbos; a notice respecting a geological 
map of the Subhercynian Hills, and an essay on the geological to- 
pography of that country, by M. Frapolli; a note on the mode of 
occurrence of the Iceland spar m Iceland, by M. Descloizeaux ; and 
a note by M. Nérée Boubée on the relation between the nature of 
soils and the different antiquity of the alluvions in valleys marked by 
different stages or levels. 
It should be observed that the Bulletin of the Geological Society 
of France contains the observations of those present at the different 
meetings upon the papers read before them, and that among them 
there are remarks of great value, both as respects the memoirs be- 
fore the Society, and points of geological interest and importance 
connected with them. Indeed many a remark, as in the discussions 
upon papers read before us, may be considered as the foundation for 
