Members of the family Corydalidae share some superficial commonalities with Trichoptera, but on careful inspection one can see the two pairs of anal claws that help place it in the order Megaloptera. The size of mature larvae is impressive; specimens from some genera exceed 8 cm in length. The abdominal segments have ribbon-like gills on the lateral portions. The mouth has mandibles that are serrated and used for biting prey. They can be confused with the more slender whirligig beetle larvae; whirligig larvae also have simpler jaws. Nigronia is the genus we most frequently encounter.