Jassidae of Illinois

The insects included under the name Jassidae, form a large and well-defined natural group. They are readily distinguishable from members of the allied families as follows: from Cicadidae by the possession of but two ocelli (or none) instead of three, as in the latter family; from Cercopidae by having broad transverse posterior coxae instead of conical ones, and having the posterior tibiae prismatic instead of round; and lastly, from Membracidae by having the thorax only slightly convex and not strongly declivous. Aside from this there is a general resemblance between forms of the same family, so that they may be very readily distinguished at a glance; but the above characters are useful chiefly for 'doubtful cases, before the student becomes familiar with the various forms.