8o 
THE STUDY OF INSECTS. 
FF. Under wings folded lengthwise. Mouth-parts formed 
for biting, p.104. Orthoptera. 
CC. The two pairs of wings similar, membranous. 
D. Last joint of tarsi bladder-like or hoof-like in form and 
without claws, p. 119.. Physopoda. 
DD. Last joint of tarsi not bladder-like. 
E. Wings entirely or for the greater part clothed with scales. 
Mouth-parts formed for sucking, p. 191... LEPIDOPTERA. 
EE. Wings naked, transparent, or thinly clothed with hairs. 
F. Mouth-parts arising from the hinder part of the lower 
surface of the head, and consisting of bristle-like organs 
inclosed in a jointed sheath. (Homofit era?) p. 121. 
Hemiptera. 
FF. Mouth-parts in normal position. Mandibles not 
bristle-like. 
G. Wings net-veined, with many veins and cross-veins. 
H. Tarsi consisting of less than five segments. 
I. Antennae inconspicuous, awl-shaped, short and 
slender. 
J. First and second pairs of wings nearly tha 
same length ; tarsi three-jointed, p. 89. 
Odonata. 
JJ. Second pair of wings either small or wanting; 
tarsi four-jointed, p. 86.Ephemerida 
II. Antennae usually conspicuous, setiform, filiform 
clavate, capitate, or pectinate. 
J. Tarsi two- or three-jointed. 
K. Second pair of wings the smaller, p. 98. 
Corrodentia. 
KK. Second pair of wings broader, or at least 
of the same size as the first pair. p. 93. 
Plecoptera. 
JJ. Tarsi four-jointed; wings equal, p. 95. 
Isoptera. 
HH. Tarsi consisting of five segments. 
I. Abdomen with setiform, many-jointed anal fila¬ 
ments. (Certain May-flies.) p. 86. Ephemerida. 
II. Abdomen without many-jointed anal filaments. 
J. Head prolonged into a trunk-like beak. 
p. 184 . Mecoptera. 
J. Head not prolonged into a beak. p. 175. 
Neuroptera. 
