C68 



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 lum- 

 bar vertebra lias been recently broken off close to the base, probably 

 the injury referred to in Dr. Joass's letter. 



On 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. 

 The 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 



