EXPLANATION OF THE PLATES. 



PLATE I. 



Fig. 1. Gom[ihus vulgatissimus ; A, labium ; c, appendices. 

 " 2. Ilerpetogomphus ; 6, labium ; c, side view. 



3. Gomphus pilipes V a, side view ; b, labium ; c, appendices. 

 ■' 4. Ictinus ; a, side view ; b, labium ; c, appecidiees ; d, lateral border of the abdomen ; e, the 



same (the tip) more magnified. 

 '■ .'). Gomphoides, species No. 10; a, side view; b, labium; c, appendices; d, head. 



PLATE n. 



Fig. 1. Macrogomphus spiniceps ; a. side view ; b, head ; c, two last joints of the antenna. 



2. Gomphus, species No. 7 ; b, labium ; c, the same (the tip) more magnified ; d, bristles of 

 the labium border. 



" 3. Progomphus ? ? a, side view ; b, labium ; c, bristles of the labium border. 



" 4. Gomphus, species No. 4 ; b, labium. 



" u. Gomphus, species No. 5. 



" U. Gomphus, species No. 6 ; b, labium. 



PLATE III. 



Fig. 1. Cordulegaster bidentatus ; a, side view ; b, labium ; c, head ; d, bifid tip of the labium. 



'• 2. Cordulegaster Sayi. 



" 3. Cordulegaster annulatus ; b, appendices. 



" 4. Hagenius brevistylus : a, side view ; c, head ; d, wing-cover. 



" 5. Hagenius Japonicus ; c, head. 



