HEX A POD A. 
8l 
GG. Wings with branching veins and comparatively few 
cross-veins, or veinless. 
H. Tarsi two- or three-jointed. 
I. Posterior wings smaller than the anterior, 
p. 98 .CORRODENTIA. 
II. Posterior wings as large as or larger than the 
anterior ones. (Certain Stone-flies .) p. 93. 
Plecoptera. 
HH. Tarsi four- or five-jointed. 
I. Abdomen with setiform, many-jointed anal fila¬ 
ments. (Certain May-flies .) p. 86. Ephemerida. 
II. Abdomen without many-jointed anal filaments. 
J. Prothorax horny. First wings larger than the 
second, naked or imperceptibly hairy. Second 
wings without, or with few, unusually simple, 
veins. Jaws (mandibles) well developed. Palpi 
small, p. 599. Hymenoptera. 
JJ. Prothorax membranous or, at the most, 
parchment-like. Second wings as large as or 
larger than the first, folded lengthwise, with 
many branching veins. First wings naked or 
thinly clothed with hair. Jaws (mandibles) in¬ 
conspicuous. Palpi long. Moth-like insects, 
p. 186.Trichoptera. 
LIST OF ORDERS OF THE HEXAPODA. 
Hemiptera. 
Neuroptera. 
Mecoptera. 
Trichoptera. 
Lepidoptera. 
Diptera. 
SlPHONAPTERA. 
Coleoptera. 
Hymenoptera. 
Thysanura. 
Ephemerida. 
Odonata. 
Plecoptera. 
Isoptera. 
Corrodentia. 
Mallophaga. 
Euplexoptera 
Orthoptera. 
Physopoda. 
7 
