VOL. XLIII, NO. 516 



DECEMBER, 1909 



THE 



AMERICAN 

 NATURALIST 



A MONTHLY JOURNAL 

 Devoted to the Advancement of the Biological Sciences with 

 Special Reference to the Factors of Evolntion 



CONTENTS 



I- The Cuticula and Subcuticula of the Trematodes and Cestodes. Professor 

 HENRY S. PRATT 1 



H. The American Toad (Bufo lentiginosus americannB, LeConte). NEWTON 

 MILLER • ' ' 1 



III. Observations on Copnlation among Crawfishes] with Special Reference to 



IV. Shorier Articles 



ing. Professor C. B. Davestokt. A Note on the Prairie-dog Owl which Re- ^ 



s and Literature : The Causation o 

 x to Volume XLIII. . 



THE SCIENCE PRESS 

 LANCASTER, PA. GARRISON, N. Y. 



NEW YORK: SUB-STATION 84 



