Lecidea geographica, Schær., 258.
lapicida, Ach., 257.

melancheima, Tuckerm., 260.
milliaria, Fr., 260.

Morio, Schær., 258.

panæola, Ach., 257.

parasema, Fr., 259.

premnea, Ach., 259.

sabuletorum, Fr., 260.

sanguinaria, Ach., 259.

variegata, Fr., 257.

vesicularis, Ach., 256.

Wahlenbergii, Ach., 256.

Lecideaceæ, Fr., 197, 236.

Leptogium, gen., Fr., 281, 284.

Burgessii, Fr., 284.

lacerum, Fr., 284.

Tremelloides, Fr., 284.

LEVERRIER, M. On comets, 296. On the comets of Lexell, Faye,

and De Vico, 296–300.

Lexell's comet, 296.

LIBRARY, donations to, by

Academy, Bavarian, 37, 182, 344, 345.

Academy of Berlin, 42, 343.

Academy of Bonn, 344.

Academy, Royal, of Brussels, 42, 43, 343.

Academy, Irish Royal, 4, 181.

Academy of Natural Sciences, Philadelphia, 181, 345.

Academy, Imperial, of St. Petersburg, 4, 37, 157, 343.

Adams, J. C., 157.

Association, British, 36, 42, 182.

Association, Geological, 4.

Association, Mercantile Library, of New York, 344.

Bache, A. D., 344.

Barratt, Dr., 156.

Biot, M., 181.

Bonaparte, C. L., 181.

Bond, W. C., 156.

Borden, S., 4.

Challis, C. J., 4, 157.
Cipri, Gaspar, 42.
Cramer, Charles, 155.
Dana, J. D., 181, 344.

De Candolle, Alphonse, 164.
Espy, James P., 182.

Everett, A. H., 3, 157.

Everett, Edward, 36, 42.
Gould, A. A., 42, 156.
Government, British, 344.

Graham, J. D., 156.

Gray, Asa, 37, 156.

Gray, Francis C., 343.

Hausmann, Professor, 344, 346.

Holtzapffell, C., 156.

Horsford, E. N., 156.

Institute of France, 181.

Institute, National, for Promotion of Science, 155.

Jomard, 36.

Journal, Italian, 345.

Journal, Silliman's, 156, 157, 181, 344.

Kriel, Karl, 182.

Lamont, F., 38.

Lasaulx, 182.

Leidy, Joseph, 345.

Loomis, E., 345.

Lyceum of Natural History of New York, 38, 182.

Marshall, George P., 344.

Martius, K. F. P., 37, 38.

Metternich, Prince, 344.

Morton, S. G., 4, 37.

Murchison, R. I., 181.

Museum, British, 181.

Northumberland, Duke of, 182.

Observatory, National, Washington, 156.

Observatory of Prague, 182.

Parsons, Usher, 344.

Pickering, John, 42.

Quetelet, A., 43, 343.

Redfield, W. C., 156.

Regents of the University of the State of New York, 182, 345.

Rich, O., 4, 42.

Sepp, J. C., 343.

Sheepshanks, R., 343, 344.

Smee, Alfred, 181.

Society, American Philosophical, Philadelphia, 4, 181, 344, 345.

Society, Astronomical, Royal, 157.

Society, Botanical, Ratisbon, 182.

Society, Ethnological, Paris, 343.

Society, Franklin, Providence, 181.

Society of Natural History of Geneva, 346.

Society, Geographical, Royal, 157.

Society of Göttingen, 346.

Society, Historical, of Massachusetts, 37.

Society, Linnean, London, 157, 345.

Society of Naturalists, Moscow, 345.

Society, Oriental, American, 182.

Society, Royal, London, 4, 157, 181, 345.

Sullivant, W. S., 3, 156.

Survey, United States Coast, 157.

Medal of the King of Denmark, for the discovery of telescopic comets,
301.

Meetings, Annual, 1, 158.
MEMBERS, Corresponding.

Baird, Spencer F., 302.
Courtenay, Edward H., 185.
Jewett, Charles C., 163.
Mitchel, O. M., 185.
Robinson, Edward, 163.

Swift, W. H., 185.
MEMBERS, Honorary.
Adams, John C., 164.
Agassiz, Louis, 36.
Decaisne, Joseph, 36.
Leverrier, M. U. J., 164.
Northampton, Marquis of, 2.
Smyth, William H., 184.
Verneuil, Edouard de, 36.

Whewell, Rev. Dr., 164.

Membranaceæ, Fr., 207.

Membranes, permeability of, to air, water, and various solutions, 302.

Mercury, transit of, 14.

Meteor, remarkable, 329.

Meteorological observations, 44, 158, 300.

Meteors, notes on, 21.

MITCHELL, MISS, comet of, 183.

MITCHELL, WILLIAM.

Account of a remarkable meteor seen from

Nantucket, March 6th, 1848, 329.

Moon Culminations, 5, 70, 103, 110, 170, 175.

N.

Nebulæ in Andromeda, 300, 326.

Nebulæ Herschel, 326.

Nebula of Orion, 326, 342.

Nephroma, gen., Ach., 197, 210.

arcticum, Fr., 210.

Helveticum, Ach., 210.

parile, Ach., 210.

resupinatum, Ach., 210.

Neptune, planet, 50, 57, 65, 144, 146, 168, 185.

Neptune, action of, upon Uranus, 332, 338.

Neptune, elliptic elements of, 285, 331.
Neptune, formulæ for perturbations of, 286.
Neptune, satellite of, 184, 185, 295.

0.

Ochroleuca, Fr., 221, 244.

Officers, 3, 163.

Olivaceo-fuscæ, Fr., 220.

Opegrapha, gen., Humboldt, 198, 266.

abnormis, Ach., 268.

atra, Pers., 267.

herpetica, Ach., 267.

inusta, Ach., 268.

polymorpha, Ach., 268.

scripta, Ach., 268.

varia, Pers., 267.

Opossum, on the generation of, 178.

Orion, great nebula of, 326, 342.

OWEN, RICHARD. On the generation of the opossum, 178.

Parmelia, gen., Ach., 197, 215.

P.

albella, Ach., 232.

aleurites, Ach., 219.

ambigua, Ach., 222.

atra, Ach., 232.

badia, Fr., 232.

Borreri, Turn., 218.

cæsia, Ach., 226.

cæsio-rubella, Ach., 232.

calcarea, Ach., 234.

caperata, Ach., 221.

centrifuga, Ach., 222.

cerina, Ach., 234.

cervina, Sommerf., 230.

chrysoleuca, Ach., 229.

chrysomelæna, Ach., 230.

chrysophthalma, Ach., 223.
ciliaris, Ach., 224.