THE MOLLUSKS OF OUR CELLARS. 169 
milk-like mueus at any part of their body which may require 
protection from any foreign substance. This secretion of 
mucus is their only means of defence against their enemies. 
It also is used as a thread like the spiders web to enable 
them to descend to the earth. 
All the species mentioned below are of foreign origin. 
They were imported from England. They are found only 
in close proximity to man around his habitation, either in 
cellars or gardens. Most of them were noticed pig y. 
more than half a century ago, as early as mollusks 
became to be studied in our country. They have 
also been imported into other colonies of England, g 
and probably are destined to become the most em 
cosmopolitan of mollusks. adips eid 
We will now describe the various species found «eerie. 
in our cellars, commencing with the only one which bears a 
well developed external shell (Fig. 44). This is the Hyalina 
cellaria, a thin, horn colored, glistening, flattened shell of five 
whorls, and less than half an inch in diam- Fig. 44a. 
eter. The edge of the aperture is sharp, not 
reflected, or dienai by a border of testa- V B 
ceous matter. It isa common European shell Animal of Hyatina 
of which a single specimen was first noticed — ^^ 
by a gentleman in Philadelphia on a wharf near the foreign 
Shipping. It was shown to Mr. Say, who described it as a 
new species. Of late years it has not been seen in that 
city, but from Astoria, Long Island, to Halifax, it exists in 
almost every Atlantie port. It is found only in cellars and 
gardens. It used to be very common under the bricks of 
the inner edge of the sidewalk on the north side of Mount 
Vernon street, Boston, between Walnut street and Louisberg 
Square. 
Limax maximus is the largest of our cellar slugs (Fig. 45). 
It seems to be a more recent importation than the other spe- 
cies, having first been noticed in Philadelphia in 1867. It 
appeared almost simultaneously at Brooklyn, New York, and 
AMER. NATURALIST, VOL. IV. 22 
