Perry.] 1630: [April 24, 
of nodules of the pyrites, which begins around the edges, as they 
are exposed at the surface, and as the chemical action proceeds 
towards the centre successive leaf-like layers are thrown out. Larger 
nodules or rounded masses give rise to a wreath-like arrangement by 
the same chemical action taking place along the edges in contact with 
the limestone. , : 
Where the pyrites was disseminated in small grains or crystals 
throughout the rock, a nearly uniform coating covers the surface, or, 
im some places, needle-like, delicate fibres are thrown out. On 
some of these fibres may be seen an indication of a periodic 
srowth, in a succession of rings or wrinkles on the surface. These 
rings are probably produced by an annual growth, as in the case of 
the horns of certain animals. During the long, dry summer of that 
recion the erowth of the fibres ceases for want of water to carry on 
the chemical action, and is renewed when the autumn rains appear. 
There is proof that this process is still going on, from year to year, in 
the fact that the forms may be seen in all stages of growth —in 
some cases just beginning where a previous coating of gypsum had 
been thrown off. 
The thanks of the Society were voted to Mrs. W. BR: Ale 
ger for a fine specimen of the female flowers of the Coco-Nut 
Palm. 
Section of Entomology. April 24, 1872. 
Mr. J. H. Emerton in the chair. Ten members present. 
Mr. Sanborn called attention to a wasp’s nest, presented 
by Luther Hills, Esq., showing a deviation from the usual 
plan of construction. The portion of the nest built the first 
year had been closed up, forming, as it were, a pedicel, to 
which the second year’s work was attached at the mouth. 
Dr. Hagen*read a letter from the Baron de Selys-Long- 
champs, acknowledging the receipt of specimens of Pseu- 
doneuroptera belonging to the Society’s collection, aud 
presenting a copy of his Synopsés des Cordulines. 
