PROF. N. H. WINCHELL,
DEAR SIR: I have the honor herewith to make another contribution to the entomology of Minnesota. As neither time nor means are yet at hand to undertake a systematic work of the whole field of entomology, as contemplated by the law creating the survey, I have, as heretofore, given special attention only to some group or family, as circumstances and literature at hand make it possible to do anything like presentable work. The following paper is a second contribution on the family of plant-lice, or Aphididre, a preliminary list of which was given in the last annual report. The two past seasons have enabled me not only to make some corrections to this list, but also several additions, which I have now put in the form of a synopsis of the family as far as known to occur in Minnesota. I am aware of the fact that shortcomings will be found, and that probably a too hasty conclusion has been drawn in many cases, but, as this is a first attempt of a systematic treatment of our American forms, I have some hopes that it will still be received with favor by all who will have occasion to use it, and that it will prove a valuable contribution to the entomology of Minnesota.