PLATE IV. 
A. — Amphorophora rubi, head of apterous form. 
B. — Amphorophora rubi, cornicle. 
C. — Amphorophora rubi, cauda. 
D. — Rhopalosiphoninus laty siphon, head of alate form. 
E. — Rhopalosiphoninus laty siphon, cornicle of alate form. 
F. — Rhopalosiphoninus latysiphon, cauda of alate form. 
G. — Myzocallis coryli, cornicle. 
H. — Myzocallis coryli, cauda and anal plate. 
I. — Callipterus juglandis, cornicle. 
J. — Callipterus juglandis, cauda and anal plate. 
K. — Therioaphis tiliae, cornicle. 
L. — Therioaphis tiliae, cauda and anal plate. 
M. — Monellia caryella, cauda and anal plate. 
N. — Monellia caryella, cornicle. 
0. — Chromaphis juglandicola, cornicle. 
P. — Chromaphis juglandicola, cauda and anal plate. 
Q. — Euceraphis betulae, cauda and anal plate. 
It. — Euceraphis betulae, cornicle. 
S. — Calaphis betulella, cauda and anal plate. 
T. — Calaphis betulella, cornicle. 
U. — Calaphis betulella, fore wing. 
V. — Saltusaphis scirpus, head of apterous form. 
W. — Saltusaphis scirpus, cauda and anal plate. 
X. — Thripsaphis balli, head of apterous form. 
Y. — Neothomasia populicola, cornicle. 
Z. — Neothomasia populicola, cauda and anal plate. 
AA. — Periphyllus negundinis, cauda and anal plate. 
BB. — Periphyllus negundinis, cornicle. 
CC. — Chaitophorus populi, cauda and anal plate. 
DD. — Symydobius oblongus, cornicle. 
EE. — Symydobius oblongus, cauda and anal plat'. 
FF. — Phyllapkisfagi, cauda and anal plate. 
GG. — Phyllaphis fagi, cornicle. 
HH. — Tamalea coweni, cornicle. 
II. — Tamalea coweni, cauda and anal plate. 
JJ. — Drepanaphis acerifolii, oviparous abdomen. 
KK. — Drepanaphis acerifolii, cauda and anal plate of alate form. 
LL. — Drepanaphis acerifolii, cornicle. 
MM. — Drepanosiphum platanoides, cornicle. 
NN. — Melanoxantherium populifoliae, cornicle. 
00. — Melanoxantherium populifoliae, cauda and anal plate. 
PP. — Pterocomma populeus, cornicle. 
141613°— 20— Bull. 826 7 97 
