Structure.

http://en.wikipedia.org/wiki/Pelvis

The pelvic region of the trunk is the lower part of the trunk, between the abdomen and the thighs.It includes several structures:

• the bony pelvis (or pelvic skeleton), which is the part of the skeleton embedded in the pelvic region of the trunk, subdivided into:
  • the pelvic girdle (i.e., the two hip bones, which are part of the appendicular skeleton), which connects the spine to the lower limbs, and
  • the pelvic region of the spine (i.e., sacrum, and coccyx, which are part of the axial skeleton).