4 PREFACE 



credited to their proper authors. The attempt has been made 

 to get classifications that can be understood by the students 

 of the grade in which this book will be used, rather than 

 those intricate tables which can be used only by a trained 

 naturalist. 



For any errors in the classifications or in other parts of 

 the book, the author alone is responsible ; and the corres- 

 pondence of his fellow teachers concerning any part of the 

 book which may be improved, is earnestly solicited. 



J. A. MERRILL. 



State Normal School, West Superior, Wis. 



