NOTICES OF SERIALS. 
27 
from the appearances we have just described. In the Brachyura , where the organs 
are most fully developed, there is attached to the operculum a long, osseous tendon 
or lever, by which the attached muscles raise or close the entire organ, but there 
is no internal structure of any kind which could identify it as being an organ of 
sound. The aqueous sac mentioned by Edwards, I have entirely failed to discover. 
Viewing the two antennae each as a whole, in their relative positions and con" 
nection with the rest of the animal, we are forcibly led to the conviction that the 
upper antenna is an organ of hearing, and the lower antenna is an organ of smell.” 
The author’s views are illustrated by plates. (M. de Quatrefages) On Double Mon¬ 
strosity in Eishes. Proceedings of Learned Societies—Linnean Society, De¬ 
cember 5, 1854, W. Yarrell, Esq., V.P., in the Chair; December 19, T. Bell, 
President, in the Chair. Zoological Society, February 14, 1854, Dr. Gray, Vice- 
President, in the Chair ; read, notes on the habits of Indian Birds, by Lieutenant 
Burgess; February 28, 1854, Dr. Gray, Vice-President, in the Chair. Boyal 
Institution of Great Britain, April 20, 1855., W. B. Grove, M.A., Q.C., F.B.S., 
Vice-President, in the Chair. Botanical Society of Edinburgh, April 12, 1855, 
Professor Balfour, President, in the Chair. Miscellaneous—Nereis bilineata, by W. 
Thompson; On a New Species of Thallasidroma, by G. B. Gray, F.L.S., andF.Z.S.; 
On the Eggs of Otogyps and Prosthemadera, by H. F. Walter. Meteorological 
Observations and Table for May, 1855. 
No. 92, August:—(T. B. Jones, F.G.S.) Notes on Palaeozoic Bivalved Ento- 
mostraea—No. 1, Some Species of Beyrichia from the Upper Silurian Limestones 
of Scandinavia—with a Plate; (J. W. Griffith, M.D., F.L.S.) On the Conju¬ 
gation of the Diatomacese—with a Plate ; (Thomas Wright, M.D., F.B.S.E.) On 
a New Genus of Fossil Cidaridae, with a synopsis of the species included therein ; 
(T. Horsfield, M.D.) Brief Notices of several New or Little-known Species of 
Mammalia lately discovered and collected in Nepaul, by Brian Houghton Hodgson ; 
(William Clarke) On the Assiminia Grayana and Bissoa anatina ; (T. Blackwall, 
F.L.S.) Descriptions of two newly-discovered species of Araneidea; (J. Gwyn 
Jeffreys, F.B.S.) Note on the Descent of Glaciers. No less than five various 
theories have been proposed to account for the descent of glaciers—1st, by De 
Saussure, who supposed that glaciers descended solely by their own weight; 2nd, 
by De Charpentier, and adopted by Agassiz, who supposed that the phenomenon 
was caused by the surface of the glacier being thawed during the day, that the 
water thus produced percolated the porous material, and that upon congelation 
taking place at night, the whole structure expanded in every direction, naturally 
occasioning or accelerating a downward movement in the direction of the slope; 
3rd, that of Professor James Forbes, which attributed it to the viscous or plastic 
nature of the glaciers, causing the descent suis viribus ; 4th, that of Mr. Hopkins, 
who referred the motion of a glacier to the dissolution of the ice in contact with the 
rock; and, 5th, that of Bev. H. Mosley, who supposed that it was caused by the 
heat of the sun, and, consequently, to an alternate expansion and contraction of the 
material. Without either patronizing one or any of these various and seemingly 
conflicting theories, or attempting to make up “ the half dozen,” Mr. Jeffreys is of 
opinion that each and all of the forces above mentioned may have their own part 
in producing this curious phenomenon; by this means he reconciles the various 
theorists, and good-naturedly sets at rest this difficult and vexed question. 
