gentleman made extensive studies of the Pterophoridae, and se- 

 cured the types of Fitch's species and all of his notes on them ; 

 but, having abandoned the work because of other engagements, I 

 obtained his entire collection of these insects, including all of his 

 own types as well as those of Fitch. Valuable notes by other 

 writers have also been made, which will be referred to under the 

 various species on following pages. 



STRUCTURE. 



* 



The Pterophoridae are small, slim insects, with long, slender 

 lugs and long, narrow fore wings, cut by a fissure extending in 

 from the middle of the outer margin between veins 4 and 7, from 

 a fourth to one-half of the length of the wing (plates II. and III.). 

 The parts on each side of the fissure are called lobes, the anterior 

 one being called the first lobe and the other the second lobe. In 

 some of the genera these lobes are narrow and pointed, while in 

 others they are well developed and present two well-marked angles 

 on each, which are called the apex and anal angle (Plate II., fig. 

 1 ) . The normal number of veins in the fore wings is twelve, but 

 this number is reduced in many of the species. Vein 1 is feebly 

 forked at the base, at least in some of the species, and the cross 

 vein and veins 5 and 6 are very weak, often entirely visible ; 5 

 and 6 at equal distances from each other and from 4 and 7, ex- 

 tending to the fissure which ends between them. Veins 8 and 9 

 are stalked and 10 sometimes arises from the same stalk, but is 

 occasionally wanting. 



The hind wings have two fissures, the first extending in from 

 the outer margin between veins 4 and 7 to about the middle of the 

 wing ; the second, between the inner margin veins and vein 2, 

 extends to about the basal fourth. These divisions are called 

 feathers, the anterior one being called the first feather, the middle 

 one the second feather and the posterior one the third feather 

 (Plate II., fig. 2). 



The first feather in some species is somewhat spoon-shaped, 

 rounded at the outer end, widest near the middle and narrower 

 near the base. The costal vein bends down near the middle of its 

 course, approaching very near to the subcostal. The costal vein 

 ends in the costa when this feather tapers gradually to a point and 

 vein 7 ends in the point. When this feather is broad at the outer 

 end and has two angles corresponding to the apex and anal angle, 

 the costal vein usually ends in the apex and vein 7 in the anal 



