4. Neurocordulia obsoleta, Say, has been taken at Cincinnati by Chas. Dury and his associates for three consecutive seasons. 5. Neurocordulia yamaskanensis, Prov., was procured on Rattlesnake Island in Lake Erie, June 28, 1900, by Prof. Osborn. 6. Nasiæschna pentacantha, Rambur, was taken near Kent, Ohio, June 21, 1900. In company with R. C. Osburn we procured three pairs of this species. Others were seen. DRAGONFLIES TAKEN IN A WEEK. RAYMOND C. OSBURN AND JAMES S. HINE. During the week beginning June 17th, we collected insects and fishes in the region of small lakes near Kent, Ohio. A list of the Odonata taken during that week is interesting, as it shows the richness of the Odonat fauna of north-eastern Ohio and also the number of species of this group that may fly in a certain locality at the same time. 1. Calopteryx maculata, Beauv. 2. Calopteryx æquabilis, Say. 3. Hetærina americana, Fabr. 4. Lestes uncatus, Kirby. 5. Lestes rectangularis, Say. 6. Lestes vigilax, Hagen. 7. Lestes inequalis, Walsh. 8. Argia putrida, Hagen. 9. Agria violacea, Hagen. 10. Argia tibialis, Rambur. 11. Argia apicalis, Say. 12. Erythromma conditum, Hagen. 13. Nehalennia posita, Hagen. 14. Nehalennia irene, Hagen. 15. Amphiagrion saucium, Burm. 16. Enallagma traviatum, Selys. 17. Enallagma civile, Hagen. 18. Enallagma carunculatum, Morse. 19. Enallagma hageni, Walsh. 20. Enallagma geminatum, Kel. 21. Enallagma exsulans, Hagen. 22. Enallagma antennatum, Say. 23. Enallagma signatum, Hagen. 24. Enallagma pollutum, Hagen. 25. Ischnura verticalis, Say. 26. Ophiogomphus rupinsulensis, Walsh. 27. Gomphus dilatatus, Rambur. 28. Gomphus quadricolor, Walsh. 29. Gomphus fraternus, Say. 30. Gomphus furcifer, Hagen. 31. Gomphus spicatus, Selys. 32. Gomphus sordidus, Selys. 33. Gomphus exilis, Selys. 34. Dromogomphus spinosus, Selys. 35. Anax junius, Drury. 36. Basischna janata, Say. 37. Epiæschna heros, Fab. 38. Æschna verticalis, Hagen. 39. Nasiæschna pentacantha, Rambur. 40. Macromia illinoiensis, Walsh. 41. Epicordulia princeps, Hagen. 42. Tetragoneuria cynosura, Say. 43. Tetragoneuria semiaqua, Burm. 44. Tramea lacerata, Hagen. 45. Libellula basalis, Say. 46. Libellula pulchella, Drury. 47. Libellula semifasciata, Burm. 48. Libellula exusta, Say. 49. Libellula incesta, Hagen. 50. Plathemis trimaculata, DeGeer. 51. Celithemis eponina, Drury. 52. Celithemis elisa, Hagen. 53. Celithemis fasciata, Kirby. 54. Leucorhinia intacta, Hagen. 55. Sympetrum rubicundulum, Say. 56. Perithemis domitia, Drury. 57. Mesothemis simplicicollis, Say. 58. Pachydiplax longipennis, Burm.