308 



INTRODUCTION TO ZOOLOGY 



leaf-like plates at the end of the body ; these are trachea! 

 gills. It swims by rapid movements of the whole abdomen, 

 first to one side and then to the other. 



Genus 1. Agrion. Abdomen blue marked with black or a 

 blackish bronze. 



2. Lestes. Abdomen of the male is green, except for seg- 

 ments 1, 2, 9, and 10, which are blue ; eyes blue. The 

 female has a green body marked with brown. The 

 members of this genus rest with their wings half spread ; 

 they are not very common. 



3. Pyrrhosoma. Abdomen crimson with some bronze 

 colouring. 



Sub-family 4 : Calopteryyinae. 



The beautiful little Dragon-flies of the sub-family Calop- 

 teryginae have narrow bodies of a brilliant metallic hue, 

 their wings are broad at their free ends but narrow at the 



base, and, though 

 coloured, have no 

 stigma in the male 

 and in the female 

 a white one only. 

 The wing differs 

 also from that of 

 an A grion in 

 having many little 

 cross veins in the 

 space between the 

 thick nodal vein 

 and the base of 

 the wing. The 

 eyes are far apart 

 as in the Agrio- 

 riidae. Because of 

 FIG. 229.Oalopteryx. tne j r beauty and 



7, Imago ; L, full-grown larva or nymph. elegailCC they ai'C 



often called 



"Demoiselles" or "Kingfishers." They dart rapidly about 

 in the air, usually several together, remaining long near the 



