In a previous paper, Article 6 of Volume X of this Bulletin, I indicated that despite the fact that our state list of species of Chironomidae is larger than any list yet published for any other state in the Union it could not be considered as a complete list of all the species occurring in Illinois. The greater portion of the material upon which the previous paper was based consisted of species collected by Mr. C. A. Hart and the writer during 1914, and containing, as it did, but a small series ofcollections from a number of scattered localities it could not be expected to include all of our species. Being aware of this fact and desirous of obtaining as many species as possible, the writer during the present year has devoted most of his spare time to collecting in the vicinity of White Heath, on the Sangamon River, with a view to completing the series of Ceratopogoninae in the collection in so far as that particular locality is concerned. No material from this part of the Sangamon River was contained in that previously studied, though many of the species were obtained near Monticello, which is but a few miles down river from this point.