62 INSECT LIFE. 



J. Tarsi two- or three-jointed. 



K. Second pair of wings the smaller. Page 68. 



CORRODENTIA. 



KK. Second pair of wings broader, or at least of 

 the same size as the first pair. Page 66. 



Plecoptera. 

 JJ. Tarsi four-jointed ; wings equal. Page 67. 



ISOPTERA. 

 HH. Tarsi consisting of five segments. 



I. Abdomen with setiform, many-jointed anal fila- 

 ments. {Certain May-flies^ Page 64. .Ephemerida. 



II. Abdomen without many-jointed anal filaments. 



J. Head prolonged into a trunklike beak. Page 78. 



Mecoptera. 

 JJ. Head not prolonged into a beak. Page 77. 



Neuroptera. 

 GG. Wings with branching veins and comparatively few 

 cross veins, or veinless. 

 II. Tarsi two- or three-jointed. 



I. Posterior wings smaller than the anterior. Page 68. 



Corrodentia. 



II. Posterior wings as large as or larger than the ante- 

 rior ones. {Certain stone-Jlies.) Page 66. 



Plecoptera. 

 HH. Tarsi four- or five-jointed. 



I. Abdomen with setiform, many-jointed anal fila- 

 ments. {Certain May-Jlies.) Page 64. 



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, usually simple, veins. 

 Jaws (mandibles) well developed. Palpi small. 

 Page 85 Hymenoptera. 



JJ. Prothorax membranous or, at the most, parch- 

 mentlike. 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) inconspicuous. Palpi 

 long. Mothlike insects. Page 79. 



Trichoptera. 



