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Show 668 PROF. FLOWER ON THE SKULL OF A BELUGA. [NOV. 18, dropped their lines and sheared off. It went below near Collieburn, but was up again at Kintradwell, and still heading westward against the tide." The skeleton is that of a perfectly adult animal, all the epiphyses Fig. 2. Posterior surface of skull of Beluga, with dislocated atlas. One-third the size of nature. of the vertebrae being united to the bodies. The spine of one lumbar vertebra has been recently broken off close to the base, probably the injury referred to in Dr. Joass's letter. O n examining the skull a most remarkable evidence of old injury and subsequent recovery showed itself. The atlas has been dislocated off the occipital condyles to the left side and tilted a little obliquely, so that the right transverse process is somewhat higher than the left. Tbe dislocation has been complete, the whole of the surfaces formerly in apposition being now free from each other. The prominent inner edge of the left articular surface has passed beyond the outer edge of the condyle and lodged in the hollow which bounds it externally, and so has been prevented by the contraction of the cervical muscles from returning into its place. In this position the bones have become firmly fixed by deposit of new osseous matter around the right side of the joint, and partially covering the exposed right condyle. The aperture for the passage of the spinal cord is narrowed to a chink scarcely three quarters of an inch in greatest transverse diameter. The articular surfaces, as far as they can be seen, have preserved their normal form, and are only slightly rougher than is natural, which clearly shows that the dislocation was traumatic, and not occasioned by disease of the joint. Indeed there is no evidence of |