108 REPORTS—EXOHANGE. 
glassy felspar, (sanidine ;) some of the specimens have a felsitic matrix. Under a 
lin. the matrix is brown and granular, and a banded structure may be seen, 
probably produced by the movement of the mass when in a viscous condition. 
The interbedded crystals are of two kinds, 1st, of glassy felspar, which are 
transparent, 2nd, opaque crystals. The glassy felspar crystals are of irregular 
forms, triangular, oblong, &c. In some cases the characteristic faces of orthoclase 
may be recognised. They are traversed by irregular cracks along which, as also 
along the edges, decomposition in certain cases has set in. The glassy felspar 
contains the opaque crystals, and also well marked gas cavities. The opaque 
crystals are more regular in form, and belong to the hexagonal system. I have 
never seen biotite so opaque, but Iam disposed to call them by that name. The 
whole specimen is traversed by irregular cracks, along which decomposition has 
taken place. The cracks are filled with a yellowish deposit. When viewed with 
polarised light and crossed prisms the matrix produces a slight action, showing 
that it might be more appropriately termed felsite. This action is no doubt due 
to the great number of exceedingly fine crystals which can be detected under a 
higher power. The matrix in which these crystals are imbedded may be truly 
glassy. The felspar shows fine colouration, the prevailing colours being blue, red, 
and yellow. In several instances the edges of the crystals are surrounded by 
iris coloured rings, which mark the progress of decomposition. In some cases the 
glassy crystals contain a number of very fine acicular crystals, probably apatite. 
This phenomenon is by no means common. The fine acicular crystals are only 
found as endomorphs along with the opaque crystals. The section of Pinites 
from the Scuir of Eigg shows all the characters of a transverse section of an 
ordinary pine. The annual rings are well marked, and turpentine vessels 
exceedingly rare. The autumn cells are smaller than those formed earlier in the 
year. The decomposed portions show a rude pentagonal or hexagonal structure, 
and in the centre is a small portion of tissue still showing the characteristic 
structure, and from this part radial lines are prolonged. 
NOTTINGHAM NATURALISTS’ SOCIETY.—February 5th.—The Hon. 
Sec. (Mr. L. Lee) delivered an address on ‘“‘ Marine Aquaria,” in the course of 
which he described the methods to be pursued for the successful management of 
aquaria generally. The address was illustrated by diagrams. February 19th.— 
General Meeting, to receive a report from the committee appointed at the last 
Annual Meeting to consider the rules of the society. March 5th.—Mr. C. 
Thornton read a paper on Animalcule, and exhibited specimens of Hydra. The 
paper gave interesting particulars of pond-life. It was illustrated by diagrams. 
Localities were mentioned where animalculz may be found. 
SEVERN VALLEY NATURALISTS’ FIELD CLUB.—March 7th.—The 
Annual Meeting was held at Bridgnorth, when the following were elected officers 
for the year :—President, Mr. T. Martin Southwell ; Vice-presidents: Mr. J. G. P. 
Smith, Mr. A. Mathias, Rev. A. T. Pelham, and Mr. 8. T. Nicholls; Secretary, 
Mr. Rowland W. Ralph, Honnington Grange, Newport, Salop. Field Meetings 
as under were arranged:—May 20th, Bewdley, for Habberley Valley and the 
Severn; June 10th, 11th, and 12th, Barmouth; July 17th, Ludlow. 
EXCHANGE. 
CorzorTEeRA.—Anchomenus puellus, for other local species.—Address, 
W.G. Buarcu, Green Lane, near Birmingham. 
Microscopic Siipes ror Excuance.—Synapta skin ; diatoms from New 
Nottingham, South Jarras, Oran, Kristianstad, Franzensbad, &c.; Helis- 
peltas, Arachnoidiscus, Isthmia, Melosira, &c.; parasites of black rat, 
mouse, pigeon, &c.; Polar: Naphthaline, sulphate of magnesia and copper, 
citric acid, stearic acid, &c.; Polycystina, Foraminifera, and anatomical 
sections stained; also insect slides —Winuiam J. Fuuuer, Broad Plain 
Soap Works, Bristol. 
