Cerci always present; usually modified into unjointed forceps.
Prominent, unjointed cerci, male with genital armature on second abdominal segment.
The Corixidae are small flattened water-bugs, with very short unjointed beak, the labrum being enclosed within the second From Marlatt, Bull.
The body is elongated and furnished with four pairs of short, unjointed, stump-like legs, each terminated by a pair of claws.
The first legs, meaning thereby the sixth pair of appendages, are generally pediform and locomotive, but sometimes unjointed, acting as a kind of brushes to cleanse the furca, while in the Polycopidae they are entirely wanting.