ADVERTISEMENTS. 
3 
TMPROVED ACHROMATIC MICEOSCOPES for Students, 
J- From £3 3 0 
Society of Arts Microscope 3 3 0 
Botanical Microscopes, with couipound powers, fitted in mahogany cases, from 
6s. 6d. and upwards. 
Stanhope and Codington Lenses, Thin Glass Circles and Squares, Plain Glasses, 
Rings, and Cells of every description, for mounting microscopic objects. Improved 
Frog Plates and Live Boxes. 
At JOHN WARNER'S Photographic and Philosophical Instrument Manu- 
factory, 72, Fleet-street, London, E.C. 
SOWERBY, CoNCHOLOGiST AND PUBLISHER, Established 50 Years, 
removing from 61, opposite the British Museum, to 164, Strand. Mr. Cal- 
VEKT, the great traveller, has carried on this business for the last few years, and 
now has determined upon removing to his Mining and Engineering Offices in the 
Strand, his large Stock of Scientific Books, Minerals, Fossils, Shells, Precious 
Stones, Cabinets, Boxes, Trays, Tablets, Tubes, Glass-top Boxes, Geological Maps, 
Diagrams, Hammers, Blowpipes, Bags and Dredges, &c., &o. 
GEOLOGICAL COLLECTIONS in great variety.— 
Class A consists of rock specimens, including all the strata from the Drift to 
the Gneiss, stratigraphically arianged, as well as the Granites, Porphyries, Sienites, 
Greenstones, Traps, Serpentine, Trachytes, Basalt, Lavas, &c. Class B consists 
of the former with the addition of the Minerals and Ores of Metals introduced 
with the rock in which they are found. Class 0 consists of Class A with cha- 
racteristic Fossils added. Class D embodies B and C, and constitutes the most 
complete and useful series that has ever been placed in the hands of the traveller 
or student. Class E represents Palaeontology only. Class F consists of the 
Geographical series of Rocks and Fossils. 
These collections have none of the muddle of the old German school about 
them, but illustrate clearly and simply the Science as it now stands according to 
our best authors, and have been adopted by the Natural History Collecting 
Association. 
CONCHOLOGY :— 
Class G, Genera of Recent and Fossil Shells ; no Geologist should be vdthout 
one of these collections. Class H, British Shells. Class I, Geographical Series. 
MINERALOGY :— 
Class K, The Earths and Ores of Metals arranged according to their chemical 
bases. Class L, Collections of Crystallized specimens. Class M, Miners' Collec- 
tions, shewing every variety of Oi-e. Class N, Architects' and Engineers' Col- 
lections, illustrating durability and hardness. 
The brilliant, living, and fine Conchological specimens collected by Mr. Calveet 
during the last twenty-three years, entirely throw in the shade the dead, faded, 
and overcleaned Sowerby Stock. 
J. F. Calvert, C.E., Mining Survey OflB.ces, 164, Strand. 
FOSSILS DISCOVERED IN THE EXCAVATIONS FOB THE MAIN DRAINAGE. 
Cyrena Dulwichiensis, Fitharella ? Rickmani, Leaves, &c. 
Sets of these Fossils from Dulwich and Peckham, numbering 15 to 20 varieties, 
from 10s. 6d. to Five Guineas, may now be obtained by enclosing Post Office 
Order (on North Brixton Office) payable to Mr. Chakles Rickman, 17, Grove- 
place, Brixton-road, Loudon, S. 
Stereoscopic Slides, Nos. 1 and 2, Cyrenea Dulwichiensis, and Limnceea ? Rick- 
mani, photographed from groups in the Bi'itish Museum, forwarded by post on 
receipt of 1 4 stamps each slide. 
