This species conforms very well with the generic diagnosis given in my previous paper, except in having the thoracic and abdominal sculpture greatly reduced. In the key to species it traces to ungavae Wly., but differs from that species, as well as from all others included in the key, in having the antennae unusually short, with the flagellar segments fewer in number and considerably stouter than in any of these species. In addition, in phygadeuontoides the thorax is notably elongate, with the mesoscutum strongly flattened, and the legs, especially the femora, are unusually short and stout; these characteristics, in conjunction with the generally black body color, being suggestive of some of the smaller Phygadeuonini.

Atmospheric convection is a process which involves the more or less vertical motion of air currents. During the discussion of winds (Part II), the writer indicated that winged insects inactivated by low temperatures, or wingless insects within any temperature zone, required vertical currents for support, and for assistance in horizontal transport, rather than horizontal currents alone, regardless of the strength of the latter currents. In the following pages, the process known as thermal convection will be considered as a means for the vertical and horizontal distribution of insects.

The following new species were bred in the course of Insect Faunal Survey work carried on in various parts of Ontario.

Coleophora salicivorella n. sp.

Palpi deep smoky, pale whitish inwardly and narrowly along ventral edge of secon joint: ventro-apical tuft on second joint well developed. Antennae with the basal joint deep smoky and slightly tufted, otherwise whitish, annulate with brown.

During the last seven years, larvae representing more than a dozen species of the genus Eupithecia have been received by the Forest Insect Survey of Canada. With the hope that some of these larvae may be recognized more readily, two species are described herewith; additional notes are given on three species already described, and a key for the separation of mature larvae of these five species is presented at the end of this article.