31 
Angulatum) was shown, the actual size of the dots 
which appeared as large pennies upon the screen, _ 
being quite beyond conception. 
Friday, r1ith, December, 1903. Sir Samuel 
Wilks, Bart., F.R.S., in the Chair. 
The following exhibits were laid upon the table 
and commented upon by the several exhibitors :— 
fossil sponges, by Mrs. Park; a collection of fresh- 
water mussels (Unionide), some being from a Highgate 
Pond, by Mr. Hugh Findon; propagative buds on the 
leaf of a moss (Orthotrichum lyellt), by Mr. L. B. Hall, 
F.L.S.; and an Ascidian (Distaplia magnilarva), by 
Dr. J. W. Williams. 
Mr. A. W. Stokes, F.I.C., F.C.S., gave a demon- 
stration on ‘‘ A Rapid Method of Dry=Mounting.”’ 
About nine-tenths of the objects supposed to be 
mounted dry, he stated, are found, in the course of 
time, to have the lower surface of their inclosing cover- 
glass bedewed with spherules of moisture or with 
minute crystals. Occasionally, the object itself is 
overgrown with fungus also. In mounting an object, 
a cell of some kind is usually needed. This may be 
formed of a ring of cement, paper, glass, vulcanite, or 
tin. In fastening this ring on to the glass slip, or in 
fixing the cover-glass, some cement must be used. 
Such cements are usually made liquid by water, 
alcohol, or turpentine. It is quite impossible, if any 
of these liquid cements are used to fasten down the 
cover-glass, for the cell to be a dry cell, since the liquid 
must dry into as well as outside of the cell. Mr. 
Stokes takes a mixture of equal parts of paraffin wax 
and bees’ wax ; a piece the size of a pea is placed on 
a glass or metal slip. This is heated till it melts and 
forms a thin film; in contact with this are placed the 
rings intended to form the cells. First one side, then 
the other side of the rings, is brought in contact with 
