A membrane surrounding the animal has a “tiny white line” along its rim, according to the study and its entire body is covered in tubercles ... to the Florida Fish and Wildlife Conservation ...

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 ...