Megaloptera is an order of insects. It contains the alderflies, dobsonflies and fishflies, and there are about 300 known species.
Megaloptera
Corydalus cornutus - MHNT
Insects are hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body, three pairs of jointed legs, compound eyes, and a pair of antennae. Insects are the most diverse group of animals, with more than a million described species; they represent more than half of all animal species.
Insect
Insect: Six legs, three-part body (head, thorax, abdomen), up to two pairs of wings
Spider: eight legs, two-part body
Woodlouse: seven pairs of legs, seven body segments (plus head and tail)