It is apparent at a glance that here was an impossible labor, since the head of the fetus could not possibly enter the pelvis, the size of which, _intra vitam_, must have been less than the above measurements by reason of the soft parts. “This is in the experience of the writer a unique case of a complete obstetric history, plus the specimens, of labor with an osteomalacic pelvis in a wild animal.” Another case may be added to those already reported by Dr. Schumann, as follows: Hairy rumped Agouti (_Dasyprocta prymnolopha_). Dystocia. An apparently normal fetus occupies the left uterine horn. The nose was engaged in the pelvis and has been moulded in a curve pointing to the right. The fetus measures—bitemporal 30 mm., cervical-coronal 31 mm., length of fetus 17 cm. Pelvic inlet in the fresh state measures 18 mm. transversely and about 17 mm. anteroposteriorly. The umbilical cord is 10 cm. long and appears normal as do the membranes. Placenta presents as a spherical mass of hard dense consistency, 35 mm. in diameter and with apparently normal placental tissue occupying the lower border of this spherical mass. On section the mass shows areas of alternating soft red tissue separated by communicating trabeculæ of dense white fibroid tissue. This mass is distinctly encapsulated, but the nature of the enclosing membrane is indeterminate. The pelvis in dry state shows evidences of malformation due to trauma. The right ileum is pushed forward and inward carrying the acetabulum a short distance inward and backward. There is a marked thickening about the right acetabulum. At the upper portion of the symphysis there is marked bending backward toward the sacrum with thickening of the bone. The last sacral vertebra is sharply bent and anchylosed, forming an angle of sixty degrees. The pelvic measurements in the dry state—at superior strait-transverse 24 mm., right oblique 23 mm., left oblique 26 mm., true conjugate 22 mm., outlet 17 mm., between the ischiatic spines. This is obviously a traumatic malformation and forms a relatively contracted pelvis. The delivery of an adult fetus is impossible.