The Canadian species of Meloidæ are few in number, but offer considerable difficulty to the student, chiefly from the fact that some of them are extremely variable in colour and size, while in the genus Meloe we meet with a group in which the specific characters have never been accurately determined. The family is characterized by the vesicant or blistering properties of its members (the “Spanish fly” being perhaps the best known in this connection), and, under the name of cantharides, blister-beetles are to be found in every drug store. To the agriculturist they are often a pest, Macrobasis unicolor often doing considerable damage to potatoes. The naturalist finds in the curious modifications of the antennæ of the males, a theme worthy of his careful study.

The genus Gnathodus, as at present accepted, includes forms closely allied to Cicadula, but differing in having only two apical cells in the wing. They are of a weaker build than species of Cicadula, and a characteristic appearance from above makes them readily distinguishable from any of that genus. The species are very variable and difficult to define. They are small, more or less slender, greenish, yellowish, or whitish Jassids, usually without distinct markings. The ocelli are distant from the eyes. The clypeus usually somewhat exceeds the genæ. The ovipositor rarely exceeds the pygofers. In the United States at least, most of the species are of very wide distribution.

In the course of identifying the Culicidæ in the National Museum collection and those received by Mr. L. O. Howard from various correspondents, for mention in a paper which he is about to publish, entitled, “Notes on the Life-history of Culex pungens, with remarks about other Mosquitoes,” three forms were met with which elearly represent new species; and as Mr. Howard desires to exclude all matter of a purely technical nature from his paper, it was deemed abvisable to publish the new species in one of our scientific periodicals.

The genus Isotoma, as far as known, is confined to the Northern Hemisphere and to the more northern part of this region. Thirty-one species are recorded from Europe and Asia, while the same number is recorded in the present paper, from the Eastern United States.