pel' vis. 1

The o eous structure formed by the innominate bones, the sacrum, the coccyx, and the ligaments uniting _ them. It articulates through the sacrum with the vertebral column, and serves as a support for the posterior limbs. 2. The cavity included within these bones. It is divided into a false, or superior, p., and a true, or inferior, p., by a plane pa ing through the promontory of the sacrum, the iliopectineal line, and the upper border of the symphysis pubis, the circumference of this plane constituting the inlet of the true p. The lower margin of the true p. is formed by the coccyx, the tuberosities of the ischia, the ascending rami of the ischia, the descending rami of the o a pubis, and the sacrosciatic ligaments. In the female all its diameters are slightly greater than in the male. 3. Any basin shaped structure or cavity. See p. of the kidney, contracted p. A p. the shape of which is changed by contraction in one or more diameters. Contracted p's are cla ified by Jarnier and Budin in six cla es, viz.: I. Pelvic anomalies due to exce of malleability of the pelvic bones. II. Abnormalities due to abnormal transmi ion of body weight to the pelvis. III. Anomalies resulting from abnormal articulation of the vertebral column with the sacrum. IV. Anomalies resulting from the abnormal direction of the upward and inward force exerted by the femors. V. Anomalies resulting from primary defects in the development of the pelvic bones. VI. Atypical deformities.