Animal with an elongate, ribbon-like body bearing an adhesive depression at the posterior end. It reaches a length of 20-70 mm and a width of 5-7 mm. The dorsal surface is reddish-yellow with three longitudinal red bands (one median and two lateral). The cephalic regions are whitish, as well as the border of the body and the ventral surface. The numerous eyes are strewn fanwise over the anterior region (C. rubrocincta-head). Tentacles are absent. The mouth and the short pharynx are situated posteriorly. The intestinal trunk extends anteriorly to the cerebral organ, with numerous pairs of lateral branches, which are not anastomosing.
The genital pores are separated. The male copulatory complex lies dorsally or posteriorly to its aperture; the prostatic organ is pyriform, interpolated; penis-papilla in penis-pocket; duplicate male complex sometimes occurs. The vagina is short; shell-chamber spacious, dorso-ventrically compressed; no [t]Lang's vesicle[/t]; the uterine canals extend into anterior third of body, where they remain separated.
Life-cycle not known.
Under stones between the tidemarks and on bryozoan colonies.
English Channel. Records also from Cape Verde Isle, Mediterranean and Japan.