IV. PREFACE. 



had our lot cast in a district in which the Land and Fresh- 

 water shells abound, perhaps more plentifully than in any- 

 other part of the kingdom ; and having noticed the never 

 failing source of pleasure, the collecting, examining, naming, . 

 and arranging of them has yielded to young persons under 

 our care, we have often urged the principals of other 

 schools to introduce the study among their pupils ; knowing 

 well, that when once an acquaintance is formed with them, 

 such is their simple elegance, that they constantly improve 

 in appearance as the acquaintance becomes more intimate, 

 and it will be found, that few who have once begun will 

 be inclined to give up, till the whole subject has been 

 mastered. 



But here a difficulty has arisen, a difficulty which we 

 hope, in some degree, the present little volume will remedy ; 

 all works on natural history are expensive, and even the 

 simplest complete works on Land and Fresh-water Shells, 

 do not form an exception to the rule. This has induced 

 many to stumble at the threshold of the science. That 

 one volume in a school may enable most of the elder boys 

 to name what they have collected, we admit ; but these 

 mostly give up the study, when they return to their 

 respective homes, for want of a descriptive manual, and 

 such as do persevere, have to trouble their friends to name 

 any species they may not have previously met with. 



These considerations, and the earnest request of many 

 of our valued friends and correspondents, in various parts 

 of the kingdom, have induced us to undertake the present 

 work ; which will be found to contain complete descriptions 

 of all the species, and other matter of a suggestive and 

 practical nature, which' the experience of several years has 

 enabled us to furnish. 



North of England Agricultural School, 

 Great Autov. 



