Most of the species recorded below were collected by the writer in the vicinity of Ithaca, N. Y. during the years 1888 and 1889. I have seen the collections of others and have found in them some forms that I had not collected. I have also examined the collection of Cornell University, and found several species not previously seen from the locality. This list is not complete, as undoubtedly more species will be found in the Cordulidæ and Gomphidæ.