Tubercles are the attachment point for spines on the test. They come in many shapes but all are constructed along the same basic plan. There is a ball-like mamelon (m) at the centre, which is the ...
The surface of heart urchin plates is covered in a mass of small tubercles marking the attachment sites for spines and pedicellariae. In the specimen illustrated tubercles are of various sizes, the ...
Some results have been hidden because they may be inaccessible to you
Show inaccessible results