the Springtails. A Class or Order of species which are apterous (wingless), have mouthparts which are recessed within the head (entognathous), have no metamorphoses, have variably developed abdominal saltatorial appendages and a peculiar ventral tube (Collophore) on the first abdominal segment, which gives the group it's name.

minute wingless arthropods: springtails

The division of Thysanura which includes Podura, and allied forms.