BIOLOGICAL BULLETIN 



fiDarine Biological Xabotator^ 



WOODS HOLE, MASS. 



Vol. XVIII 



January, 1910 



No. 2 



CONTENTS 



Page 



Smith, Frank. Hydroids in the Illinois River 67 



Wright, Albert H. The Anura of Ithaca^ N. T. : A 



Key to Their Eggs 69 



Stevens, N. M. A Note on Reduction in the Matura- 

 tion of Alale Eggs In Aphis 72 



Morgan, T. H., Payne, E., A Method to Test the Hypothesis of 



AND Browne, E. N. Selective Eertilization 76 



Andrews, E. A. The Anatomy of the Stylets of Cam- 



barus a?id of Astacus 79 



Published Monthly by the 

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