A fasciole band that encircles the adapical part of the anterior ambulacrum but does not enclose the petals, passing closer to the apical disc than any well-developed petal pore-pairs.
insert
An arrangement of apical disc plates in which the ocular plates (white) are separated from the periproct opening by genital plates (purple) (dicyclic plating).
interambulacra
pleural of interambulacrum
interambulacrum (-al)
Of or pertaining to the plates separating ambulacral zones in the corona and which are usually biserially arranged.
interporal partition
The calcite bar that separates the two pores in a pore-pair.
interradial
at or towards the centre of the interambulacral zone (direction)
interradius
Suture separating the two columns of interambulacral plates
isopore
An ambulacral pore-pair connecting tube-foot and internal water vessel composed of a pair of similar-sized pores.
