ARTHROPODA. 119 



AGXATIII. Antennae shortj setaceous, of three joints, the last 

 very long. Jaws soft, membranous or obsolete. Posterior wings 

 small, sometimes wanting. Abdomen ending in two or three 

 long setae. 



The fore legs are long in the male. The larvae are aquatic, live 

 two or three years ; the perfect insect takes no food, and dies in a 

 day or two. They sometimes appear in almost fabulous numbers, 

 and always in the evening. 



Chloeon. Palingenia. 



Oligoneura. Baetis. Ephemera (May-fly). 



Lachlania. Heptagenia. Oniscigaster. 



Caniia. Potamanthus. *Platephemera. 



*Herneristia. *Breyeria. 



ODOXATA. Antennae short, setaceous, of seven joints at most, 

 the last subulate. Jaws very strong, covered by the lips. 

 Wings subequal, reticulate. 



The abdomen in the male ends in two curved, in the female in 

 two simple appendages. The eyes are very large. The larva and 

 pupa are aquatic, the former very dissimilar to the perfect in- 

 sect ; in all stages they are voracious insect feeders. 



The three groups given below are not strictly entitled to the 

 rank of families. They are all known as " dragonflies." 



LibellulidcB. JEschnidcs. 



Agrion. Cordulia. ./Eschna. 



Lestes. Epitheca. Anax. 



Callepteryx. Libellula. Gromphus. 



Platycnemis. Diplax. Cordulegaster. 



PLANIPENNIA. Antennae elongate, many-jointed. Jaws di- 

 stinct. Wings nearly equal. 



The larvae mostly terrestrial ; in Sialidae they are aquatic, but 

 sometimes they live out of the water before transformation. 

 Pupae incomplete, inactive. Myrrneleontidas and Ascalaphidae 

 have clavate antennas. Coniopterygidae are covered with a 

 whitish powder. In Ehaphidiidae the female has an ovipositor. 

 Panorpiclae have a clypeus lengthened into a snout with very 

 small mandibles at the end. The perfect insects are generally 

 herbivorous, but the larvae are voracious insect feeders. 



