Is Mastoid Process Located Below The Temporal Bone And Shaped Like A Lump?

have two hard lumps behind my ears (one on each side, same location, size, hardness) I can also feel the edge of the bone behind each ear, then below that, a shallow indentation, and then the lumps. i have heard of the mastoid process. my question: can your mastoid process be slightly below the main ear (temporal?) bone and shaped like a lump/sphere?