188 Mrs. Sheppard on 
continually attracted thither, and there congealed and accu- 
mulated—the inclined planes on which they alight, become 
at length inadequate to the support of their mass and weight, 
they descend to lower levels—they occupy the yale below, 
whence they never are removed, being incessantly renewed 
from the same permanent sourceof supply, by the same yn- 
alterableprocess, as rapidly as any portion of them yields to, 
the temperature below; or even more rapidly in cases where 
they are observed to be encreasing. 
Arr. X.—Mrs. Sheppard of Woodfield on the 
recené shells which characterize Quebec and 
ais environs, 
a 
At the earnest solicitation of a member of the Society of 
Arts and Sciences,* I have eudeavoured to compile a list of 
such few shells, inhabiting the grounds and waters in the 
neighbourhood of Quebec, as have come within my observation: 
In making this list the system of De Lamarck has been 
followed ; it contains perhaps but a small proportion of the 
Shells which may yet be fonnd by more vigilant searchers ; 
but imperfect as is is, it possibly may have some interest with 
the Society, if it be but to induce others to prosecute this 
interesting branch of natural history. 
De Lamarck considers Conchology as part of the main body 
of Zoology ; he begins with Infusoria, and goes regularly 
step, by step, up the ladder of life, which he divides into 
animals invertibrate and vertibrate ; he has placed those 
animals with a testacious covering, in the ninth, tenth, eleventh 
and twelfth Classes of his ‘* Animeaux sans vertébres.” 
* To the writer of which a silver medal was adjudged. This article 
was kindly communicated by the society to which it was presented, to 
the Literary and Historical Society, 
