New YORK SHELL CLUB NOTES No. 264 September 1980 Page 5 
the feeding habits of the snails create more surface area upon which 
epiphytes can colonize. This creates more food f 
or ot ™ 
cies, which in turn are grazed upon by many Scie xotaliy Wawertate 
anisms, especia 
ce oies’ p lly when these organisms inhabit the marshes as 
Other marsh snails also play a role in this intera 
bean snails (MeLampus coffeus) lack operculums Sed nee eit re- 
main under moist detritus to prevent drying out. Coffee-bean snails 
also clean the stalks of cord grass and needle rush, but they prefer 
higher elevations in the marsh, since they will drown on prolonged 
immersion. The ladder-horn snail (Cerithidea scalariformis), another 
marsh species that similarly contributes to the habitat, 18 often 
found in the highest marsh elevations. These snails feed on algae 
around the bases of the salt grasses and in the sands. Like the 
salt-marsh periwinkles, the ladder-horn snails have operculums, and 
they are able to remain dormant for a considerable period of time. 
These three species provide a dramatic testimonial to the contribu- 
tions of small animals to their habitat. Considering the role that 
these gentle grazers play in the living environment surrounding then, 
Veet =: to be better understood by human visitors to the salt 
marsne 
Reprinted by permission of the author and I.0.F. from 
SEA FRONTIERS 25(6) 338-341, November-December, 1979. 

CEPAEA NEMORALIS IN THE PACIFIC NORTHWEST 
George Holm, of Richmond, British Columbia, Canada, writes in the 
club paper DREDGINGS 20(3) 5, June 1980, as follows: 
"A few species of local land snails including Monadenia fidelis Gray 
and Vallonia pulchella Muller can be found a foot or two above the 
ground on tree tr S and on bushes where shade and moisture permit, 
but as far as I know, there are no tree snails in the Pacific North- 
west. 
Therefore, I was a little surprised to see snails up to one inch in 
diameter and in colors of yellow, brown and red on the trunks and 
branches of Aspen and other scrub trees at the intersection of the 
Fraser Highway and 88th Avenue in the Municipality of Surrey in 
British Columbia, Canada. The species was Cepaea nemoralis Linne, 
but unlike the Monadenia and the Vallonia, these were observed up 
to fifteen feet above ground. 
Cepaea nemoralis Linne is an introduced species which is slowly ex- 
panding its range up the Fraser River valley away from Vancouver, 
British Columbia where it has become well established. It comes in 
colors of yellow, red and fawn and can be either banded or unbanded. 
All the colors and forms were present at this location. 
The species was very common throughout the area, both on the ground 
and amongst the grass and undergrowth, so one can only noida 
whether it is overcrowding that has sent it into the trees or tha 
our area is finally getting its own tree snail." 
In the American Museum of Natural History's GUIDE TO SHELLS from 
