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.
An arrangement of apical disc plates in which the ocular plates (white) are separated from the periproct opening by genital plates (purple) (dicyclic plating).
pleural of interambulacrum
Of or pertaining to the plates separating ambulacral zones in the corona and which are usually biserially arranged.
The calcite bar that separates the two pores in a pore-pair.
at or towards the centre of the interambulacral zone (direction)
Suture separating the two columns of interambulacral plates
An ambulacral pore-pair connecting tube-foot and internal water vessel composed of a pair of similar-sized pores.