‖ ambulacrum
(æmbjuːˈleɪkrəm, -ˈækrəm)
Pl. -a.
[L., a walk, avenue; f. ambulā-re to walk.]
An ‘avenue’ or double row of pores for the protrusion of the ambulacral tubes or tube-feet, of which five series radiate from the apex of an echinoderm.
| 1837 Penny Cycl. IX. 259/1 Species [of Echinidæ] whose ambulacra are petaloid, going from a centre..This section is divided into subsections, according to the depth of the ambulacra. 1877 Huxley Anat. Inv. An. ix. 568 At its apical extremity the ambulacrum is composed of only two small ossicles which meet in the middle line. |