They are sucked up by two cupping vessels, (“cotyloid”—cup-like—cavities,) and held there as long as you live, and longer.
In Ornithorhynchus the cotyloid or os acetabuli is a larger element of the girdle than is the pubis.
Very often a fourth pelvic element, the acetabular or cotyloid bone, occurs.
cotyloid cot·y·loid (kŏt'l-oid')
Shaped like a cup.
Relating to the acetabulum.