466 Transactions. 
geniculate ; palpi normal. Mesonotum with 2-4 pairs of dorso-centrals; 
mesopleurae with 1-3 long posterior bristles as well as generally a number 
of setulae ; one or two bristles above mid-coxae and generally numerous 
setulae ; propleural bristle strong ; squamae distinct. Ovipositor of female 
generally with base chitinized, apex seldom protruding ; male hypopygum 
of moderate size, not incurved. Legs without preapical bristle on dorsa 
surface; end spurs weak. Wings with subcostal vein weak, sometimes 
one at, or slightly beyond, wing-middle ; posterior basal cell always 
complete though small; anal vein (sixth) distinct ; costa to third vein, 
slightly beyond it, or to fourth. This last character is difficult to dis- 
tinguish sometimes, and is not of sufficient importance to permit of ie 
relegation of those species having costa to only third vein to a differen 
genus from those with costa to fourth." jtd de 
The essential character of the genus Phytomyza as differing from the 
above is the entire absence of the outer cross-vein. TÉ 
A rather remarkable difference in the dehiscence of the two genera (as 
represented in this paper) should be noticed. In a typical pupa there are 
: п. ы 
therefore, the anterior three and а half segments become divided into 
undergoes 
to belong to the head-plate, they are not lifted with it, but В 
attached to the dorsal half. qus 
puparium. n the kr 
Phytomyza, on the other hand, the head-plate consists of the. а de 
4 
