IOWA ACADEMY OF SCIENCES. 
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first fork, or first cubitus; C 2 , stem of second fork, or second cubitus; I 21 
first, second, third and fourth furcal veins respectively; c. s., claval 
suture; c/., clavus. 
The cells are designated as follows: 1, outer basal cell; 2, inner basal 
cell; 3, radial cell; 4, discoidal cell; 5, cubital cell; 6, first marginal cell; 7, 
second marginal cell; 8, anal angle. 
The same letters that are applied to the front wings are also used for the 
corresponding parts of the hind wings. 
In the venation of the hind wings notice: (1) That the radial portion of 
the subcosta is obsolete, thus leaving the outer basal cell and the radial 
cell unseparated and in the form of one long costal cell. (2) The basal por- 
tion of subcosta, discoidal portion of subcosta, and the radius form a contin- 
uous vein extending the full length of the wing. (3) The third furcal is 
obsolete, leaving the stem of second fork (second cubitus) and the 
fourth furcal as one continuous vein, and the second marginal cell in com- 
mon with the cubital cell. Otherwise the venation seems to be virtually 
the same as in the front wings, except that the marginal vein becomes 
indistinct from the stigmal part on to the clavus. 
The fine hair lines indicate the natural size of the wings. 
Figure 2. — Wings of Psylla negandinis, n. sp. The venation is the same 
as usually found in the genus Psylla, and all the veins and cells correspond 
very closely to those of figure 1. 
Figure 3. — Wings of Psylla amorphse n sp. Veins and cells named the 
same as in figure 1. » 
Figure 4. — Wings of Psylla annulata, Fitch. Veins and cells named as 
in figure 1. 
PLATE XVII. 
Figure 1. — Wings of Trioza tripunctata Fitch. Lettering the same 
as in figure 1, plate II. The same veins are represented except the 
petiolus cubiti which is wanting, thus causing the stem of the first fork 
(first cubitus) and the stem of the second fork (second cubitus) to arise from 
the same point. In the hind wings the part that would correspond to the 
petiolus cubiti is represented. 
Figure 2. — Wings of Trioza salicis n. sp. Lettering same as preceding. 
Figure 3. — Wings of Aphalara polygoni. Lettering the same as before. 
The petiolus cubiti is a little shorter than the discoidal portion of the sub- 
costa, but the other structural characters unmistakably place it in the sub- 
family Aphalarinse. The hind wings show an important difference in the 
fact that the veins marked and Cj arise from different parts of the sub- 
costa, and the part that in the other genera corresponds to the petiolus 
cubiti is wanting. 
A very faint vein arising about half way between the two forks and 
extending to what corresponds to the pterostigma, is sometimes indicated 
and might be taken to represent the radial portion of the subcosta. 
Figure 4. — Wings of Aphalara exilis, var. rumicis. Lettering same as 
before. 
