12 ILLINOIS NATURAL HISTORY SURVEY MANUAL 



may be found on the leaves of forest shrubs and other plants. 

 In fact, almost any place may harbor one or more land snails. 

 The admonition to be given the beginning conchologist is to 

 look everywhere; he may be rewarded by finding species hitherto 

 unknown in his vicinity. 



The spring and summer months when moisture is abundant 

 are best suited for the activity of snails. The most favorable 

 time for collecting them is after a rainy period in summer. In 

 late fall, and also in very dry periods, snails bury themselves in 

 the ground or under debris of some sort and close the shell 

 aperture with a secretion which forms a leathery flap called an 

 epiphragm. They may thus be found in any of the winter months 

 by a little patient digging about stumps, or under matted leaves 

 and started bark. 



Making the collection. — In collecting land snails, the con- 

 chologist should not confine his activities to living specimens. 

 Even the empty, so-called "dead" shells should be picked up if 

 they are not badly broken or bleached. Among these may be 

 representatives of some species the living specimens of which 

 are not easily found. The empty shells are just as useful for 

 establishing a record of the presence of a particular species or 

 variety as are the shells containing animals. When well cleaned, 

 they make good cabinet specimens. 



Often, close examination of the ground will reveal shells 

 of many of the small species, the interesting pupoid snails. 

 Washings from cliffs and debris along the shores of streams — 

 known as stream drift — may contain shells of many species not 

 commonly found alive. 



Keeping records. — It is of great importance for the student 

 to keep a record of his field observations in a book or on sheets 

 of paper, which may be called field data blanks. This record 

 should give the exact location of the place where each specimen 

 is found, the nature of the habitat, the kinds of trees and other 

 vegetation in the immediate vicinity, the condition of the ground 

 where the collection is made, the nature of the weather at the 

 time and the temperature of the air. 



It may be possible for the amateur collector to supply very 

 valuable information to science by keeping exact records of 

 his collecting localities. A different number should be given to 

 each collecting location even if two or more locations are in the 

 same general region. For example, in one general region there 

 may be an isolated woodland, a river valley and a railroad em- 



