Vlll PREFACE 



W. Leiig for the gift of specimens ; to S. W. Frost for the use 

 of photographs ; and to many others for similar favors. 



The drawings were made by Anna C. Stryke, Ellen Edmonson, 

 Nellie H. Crosby and C. H. Kennedy. Several of the illustra- 

 tions are from photographs previously published in bulletins 

 by the late Prof. M. V. Slingerland, by Prof. G. W. Herrick and 

 by H. H. Knight. 



C. P. Crosby. 



M. D. Leonard. 



Cornell University, Ithaca, N. Y. 

 May 28, 191S. 



