Ambulacrum (anatomy)
Appearance
![](http://upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Zeeegel3.jpg/220px-Zeeegel3.jpg)
In zoology, an ambulacrum is an elongated area of the shell of an echinoderm in which a row of tube feet are arranged. It is pluralized as ambulacra. The area on the shell between ambulacra is known as an interambulacrum.