179 
portion of the boulders and smaller masses may have been obtained, 
as proposed by Dr. Mitchell, from strata which once occupied the site 
of the German Ocean. The blocks of primary formations, he as- 
signs to a northern origin. 
Feb. 5.—Alexander Robertson, Esq., of Inverugie House, in the 
county of Moray; and William Sharpe, Esq., President of the 
Bradford Philosophical Society, were elected Fellows of this Society ; 
M. Puillon de Boblaye, of Paris, Professor Adolphe Brongniart, of 
Paris; and Professor Gustav Rose, of Berlin, were also elected 
Foreign Members. 
The President first read from the chair, an extract of a dispatch 
from Consul Chatfield, dated San Salvador, Oct. 10, 1839, and 
forwarded to the Society by Mr. Backhouse, by direction of Vis- 
count Palmerston. 
San Salvador is very subject to earthquakes, and on the 22nd of 
March, 1839, it experienced a strong shock, which was followed 
during nearly a fortnight, by ten to twenty daily, though of less 
force. ‘The shocks were afterwards continued at intervals, but as 
they were not unusually violent, they attracted no particular at- 
tention. On the first of October, at 2 a.u., a powerful earthquake 
was felt, and at 3 o’clock a second, which nearly demolished the 
town. The shocks were afterwards repeated with alarming violence 
and frequency, and at the date of the dispatch, not a house re- 
mained standing secure. The shocks were supposed to originate in 
operations immediately beneath the town, as places five or six miles 
distant had received no injury ; and the motion was considered to have 
been decidedly perpendicular. 
A paper was next read, on Orthoceras, Ammonites, and other 
cognate genera; and on the position they occupy in the animal 
kingdom, by Robert Alfred Cloyne Austen, Esq., F.G.S. 
The object of this memoir is to examine whether the fossil shells 
to which it refers, have been properly classed; or whether they do 
not belong to a higher order than that in which they are generally 
placed. Mr. Austen is of opinion that the shells of cephalopods were 
enveloped in the body of the animal; first, on account of the appa- 
rently extreme tenuity of certain genera, as Turrilites, Scaphites, 
Clymene, Cyrtoceras, Baculites, and Ammonites, which would render 
the shell extremely liable to injury. Secondly, from the mouths or 
openings of the outer chambers of some cephalopods being exceed- 
ingly contracted, as in the genera Scaphites and Baculites, in which 
the upper edge of the outer chamber is so nearly in contact with the 
body of the shell, or is so bent over, that the chamber could not have 
served, he conceives, as a place of retirement for the animal: certain 
Orthocera, O: pyriforme, O. ventricosa, are also mentioned by Mr. 
Austen as having the last chamber closed, or perforated only for the 
passage of the siphunculus; and he refers to the capacity of the 
outer chamber of Ammonites Calloviensis, A. depressus, A. canalicu- 
Jatus, A. discus, A. sublevis, A. Gervillit and A. funiferus, being so 
