Describe the distinguishing characteristics of the bones of the pelvic girdle.

The human pelvic girdle is a masterpiece of divine
creation!  It is the synchronous melding of bone to bone, joining the legs to the spinal
column in a supple, strong fashion as well as creating a basin to house the digestive,
eliminatory, and reproductive organs of the
body. 

Pelvis means "basin" in Latin. 
It is made up of some queer bones called "ossa innominata" or
"bones without a name".  The reason why is because they are so
irregular in shape, it's hard to know if they are all one bone or a series of  bones
joined together!  To simply things, scientists have broken down the
innominate bones into three basic parts: 
ilium, ischium, and
pubis. 

The
ilium is the uppermost prominent bone of the pelvis and is often referred
to as the "groin" or "flank".  It is also the
widest part of someone's hips and the part you can feel the most.  The
ischium forms the lower and back part of the hip and is
referred to as the "hip".   It's also the part of the pelvis that
the leg is attached to via a ball and socket joint and many ligaments and connective
tissue.   The pubis is the "floor" of
the pelvis and the bones we feel when we're sitting.   The male and female pelvis are
shaped differently, the female pelvis having the capability for spreading wider during
childbirth.  The birthing child descends through a special opening in the female pelvis
called "the birth canal."  The hips attach to the spinal column via
the sacrum, the lower continuation of the spinal column and
above the coccyx, or "tip of the
spine."

So, remembering the song, "Them Bones,
Them Bones," it goes like this:  "The thigh bone's connected to the hip bone; the hip
bone's connected to the backbone; the backbone's connnected to the headbone . . . " and
so on and so forth!  It's really quite ingenious and also very strong!   The upper body
rests on the hips, the hips rest on the legs, and everything's held together by
ligaments and connective tissue.   

By the way, I looked up
each one of the names of the bones in a dictionary, the World Book Encyclopedia, and on
Wikipedia.com.