Cape Hyrax (_Hyrax capensis_). Impossible labor due to malformation of the pelvis. This animal died as the result of shock and exhaustion of labor. She was pregnant of two fetuses, one of which was extracted manually by the keeper but was dead at birth. Twenty-four hours later the animal was found dead. On autopsy there was present a fully developed fetus in the right cornu, the head just above the pelvic inlet. The left cornu was large and boggy. The myometrium of the right side was so thin as to be almost transparent. On examining the bony pelvis the reason for the dystocia is at once apparent. The sacrum is tilted to the right, and the body of the left ileum is bent sharply to the right, the pelvic inlet being obliquely contracted, the right oblique diameter being 16 mm. while the left is 23 mm. The pelvic obliquity made the birth of a full sized fetus impossible, the one delivered being under developed. The myometrium was evidently stretched almost to the point of rupture when death occurred. Obstruction to the birth canal by abnormalities in the soft parts, such as muscular rigidity, edema, or inflammation, tumors, atresia or developmental defects are occasionally seen by veterinarians but have not been encountered here. Dystocia from uterine displacements are uncommon except such as may depend upon the failure of support by the abdominal wall, since this is the principal support of the organ especially when gravid. Hernia or hysterocele is known and anteflexion has been seen. Torsion, a rare human condition, is not uncommon in lower animals probably due to the loose dependent position of the pregnant cornua, attached only to the pelvic walls by slender inactive suspensory ligaments. A case may be reported, not originally described. Canada Porcupine (_Erethizon dorsatus dorsatus_). Obstructed labor. This animal died from exhaustion due to an impossible labor. On autopsy the abdomen contained a moderate amount of clear serous fluid with one small blood clot. The right uterine cornu was distended with a fetus to about the same diameter as the uterine body. This cornu was congested and edematous and its walls very thin. The cornu was twisted one-half full turn from right to left, so that the pregnant portion overlaid the uterine body anteriorly. The torsion produced a compression of the vessels on the right side to the point of violent congestion of the cornu. There was no apparent rupture of the uterine walls, death having occurred from exhaustion. The fetus and its membranes were normal. Many forms of abnormalities in position are recognized for domesticated animals, but since we know so little of the early stage in the wild specimens no data can be given.