VI PREFACE. 



science of Zoology. So far from advancing its progress, 

 it may be said unhesitatingly that they tend only to retard 

 it. It is through such channels that errors already of 

 long standing become more widely circulated, at the same 

 time that new ones, to a greater or less extent, are in- 

 fallibly introduced. The author who is too indolent to 

 examine and describe for himself, has often spared himself 

 the trouble of even investigating the nature of the materials 

 which he has obtained from others. The consequence is, 

 that he has perhaps blended together the descriptions of 

 two or more perfectly distinct species, or out of one made 

 several, or, led away by the identity of mere names, has 

 transferred to our native animals the descriptions of 

 exotic, nearly allied species, with which he has confounded 

 them. 



After the above enunciation of the two leading points 

 which have been borne in mind whilst preparing this work 

 for publication, the author hopes that it will not be thought 

 uncalled for by those for whose use and guidance it is prin- 

 cipally intended. The latest previous work upon the same 

 subject and conducted upon the same general plan is the 

 " History of British Animals" by Dr. Fleming. This was 

 completed in 1827 and published the year following, since 

 which period a great variety of species have been added to 

 the Fauna of this country, more particularly in the Class of 

 Fish, though many occur in the Classes of Quadrupeds and 

 Birds. As these additions have been already indicated in 

 the " Systematic Catalogue" lately published by the author 

 of the present work, it is unnecessary to dwell upon them 

 individually. It may, however, afford interest to present 

 a comparative view of the aggregate numbers of species in 

 each Class, as they appear in the " British Animals" of 

 Dr. Fleming and in the Manual now offered to the public. 



