funnel–mantle locking apparatus

The funnel–mantle locking apparatus is a structure found in many cephalopods that connects the mantle and hyponome (funnel) and restricts their movement relative to each other. It consists of two interlocking components: one located on the mantle (often fibrous) and the other on the funnel (often cartilagenous). The apparatus may permit some anterior–posterior displacement or prevent movement altogether.