Situated beneath the loins on the inner side of the muscle last described.

Origin. - From the bodies of the three or four last dorsal and all the lumbar vertebrae.

Insertion. - To a small bony eminence (ilio-pectineal) on the front of the ilium.

Action. - When the loins are fixed, it draws the pelvis forward and flexes it on the spine. When the pelvis is fixed, it roaches the back.