64 NATURAL HISTORY. 



twisted cone, whose single involution rolls or winds 

 around a small column in the interior. Many of the 

 same have an opening at the foot, which serves to close 

 the entrance of the shell, when the animal retires' into 

 it. This is the case with the aquatic snails (pulmonea 

 aquatica). Some of these snails breathe the air through 

 a kind of lungs, others have a branchial apparatus. To 

 the pulmonea, or those having lungs, belongs 



The Common Red Slug (limax rufus), which is 

 without a shell, the body is almost cylindrical, about the 

 size of a man's finger in length and thickness ; the color 

 is reddish-yellow above, gray below. They are espe- 

 cially abundant after rain, and are found always in damp 

 places, such as raoats and ditches. They lay from 

 twenty to thirty small eggs; these, covered with a parch- 

 ment-like skin, are deposited under stones, etc. Some 

 few are black. They are supposed to show the state of 

 the weather in the following manner : If they are seen 

 crawling homewards in the evening with mud on their 

 tails, bad weather may be expected ; but if they carry a 

 green leaf, the weather will be fine. They feed on all 

 kinds of plants and refuse matter. 



The Field Snail (limax agrestis) is one inch long, of 

 a foul white color, very slimy, and most injurious to 

 agriculture. Ducks are kept by many on account of 

 their useful services in ridding the fields and gardens of 

 these slugs. 



The Vineyard Snail (helix pomatia) has a body re- 

 sembling the above described, which is enclosed in a shell 

 resembling a twisted cone. These snails are found every- 

 where, in meadows, gardens, or about hedges, and towards 

 the latter part of summer appear in great numbers. They 

 can be fed on cabbage, salad, clover, etc., so as to be 



