A short strong band connects the anterior extremity of the cartilage with the rough eminence on the second phalanx in front of the attachment of the lateral ligament of the coffin joint. The lower border of the cartilage is covered externally by fibers which attach it to the wing of the third phalanx. THE ARTICULATIONS OF THE PELVIC LIMB THE SACRO-ILIAC ARTICULATION This joint (Articulatio sacro-iliaca) is a diarthrosis formed between the auricular surfaces of the sacrum and ilium. These surfaces are not smooth in the adult, but are marked by eminences and depressions, and are covered by a thin layer of cartilage. The joint cavity is a mere cleft, and is often crossed by fibrous bands. The =capsule= is very close fitting, and is attached around the margins of the articular surfaces. It is reinforced by the =ventral sacro-iliac ligament= (Ligamentum sacro-iliacum ventrale), which surrounds the joint, and is exceedingly strong above. The =movements= are inappreciable in the adult—stability, not mobility, being the chief desideratum. The following ligaments may be regarded as accessory to the joint, although not directly connected with it. The =dorsal sacro-iliac ligament= (Ligamentum sacro-iliacum dorsale breve) is a strong band which is attached to the internal angle (Tuber sacrale) of the ilium and the summits of the sacral spines. The =lateral sacro-iliac ligament= (Ligamentum sacro-iliacum dorsale longum) is a triangular, thick sheet which is attached in front to the internal angle and border of the ilium above the great sciatic notch, and below to the lateral border of the sacrum. It blends above with the dorsal sacro-iliac ligament, below with the sacro-sciatic ligament, and behind with the coccygeal fascia. The =sacro-sciatic ligament= (Ligamentum sacrospinosum et tuberosum) is a quadrilateral sheet which completes the lateral pelvic wall. Its upper border is attached to the border of the sacrum and the transverse processes of the first and second coccygeal vertebræ. Its lower border is attached to the superior ischiatic spine and tuber ischii. Between these it bridges over the external border of the ischium and completes the lesser sciatic foramen. The anterior border is concave, and completes the greater sciatic foramen. The posterior border is fused with the vertebral head of the semimembranosus muscle. The =ilio-lumbar ligament= (Ligamentum ilio-lumbale) is a triangular sheet which attaches the ends of the lumbar transverse processes to the ventral surface of the ilium below the attachment of the longissimus muscle (Fig. 184). [Illustration: FIG. 153.—LEFT OS COXÆ AND ADJACENT PARTS OF SACRUM AND FEMUR OF HORSE. (After Schmaltz, Atlas d. Anat. d. Pferdes.) ] SYMPHYSIS PELVIS