PREFATORY NOTE 



The paper on the Odonata of Ohio, by Prof. D. S. 

 Kellicott herewith presented to the public, was in such 

 an advanced stage of progress at the time of his death 

 that there can be no possible question as to the desira- 

 bility of publishing it in the form which he had given to 

 it. It was necessary, however, in order to give it the 

 completeness that would make it most serviceable in 

 the line intended by the author that the species not 

 covered in the manuscript he left should be given a 

 similar treatment. This duty has been performed by 

 Mr. J. S. Hine, whose long association with Prof. 

 Kellicott, and participation with him in the collection 

 and preparation of material on which the paper is 

 based gave him exceptional advantages for the work. 

 Of the original manuscript by Prof. Kellicott, which 

 covers everything up to and including Gomphus ex- 

 ternus nothing has been changed, except to make such 

 verbal changes as he himself would have made on a 

 final revision for the press. For the remainder the 

 effort has been to complete as nearly as possible on the 

 plan followed by Prof. Kellicott, in the portion he had 

 finished and, wherever possible, use has been made of 

 his published descriptions. 



The sketch of Prof. Kellicott's life, and the bibliog- 

 raphy have also been prepared by Mr. Hine, the draw- 

 ings for the plates by Mr. W. E. Kellicott. 



Herbert Osborn. 



Dept. Zool. and Ent. 0. S. U., Columbus, Ohio. 



Feb. 10, 1899. 



