ANATOMY OF MEGAPTERA LONGIMANA. 69 



In Table II. it is seen that, all along the column, the length 

 is considerably less than the height, back to the 17th caudal, 

 where they become about equal. 



[In B. musculus the largest bodies are those from the 3rd to the 

 7th caudal, the 5th on the whole the largest. Its height is lOf 

 inches, length 10 inches, but the 7th has the greatest breadth, 12|. 



The greatest vertebral body in Megaptera is the 2nd of its 21 

 caudal vertebrae, the 33rd of its 52 vertebra ; and it has in front of it 

 nearly 17 feet of the vertebral column, behind it, 11| feet. In B. 

 musculus the greatest body is that of the 5th of its 25 caudal 

 vertebrae, the 42nd of its 62 vertebrae ; and it has in front of it 26 

 feet of the column, behind it, 10| feet. In B. musculus the length 

 is as great as the height in the posterior dorsal region (9th to 13th) : 

 along the lumbar region, less than the height only by ^ to ^ inch ; 

 in the caudal region the difference may be only slightly greater back 

 to the llth, where the length becomes less than the height by 1^ inch, 

 and more backwards, except on the four or five posterior vertebrae 

 where the difference between the height and the length is not great. 

 In Megaptera the length is less than the height on the above-men- 

 tioned dorsal vertebrae (9th to 13th) by from 1J to 1J inch ; along 

 the lumbar region by an average of 1^-inch, in contrast with the ^ to 

 \ inch in B. musculus. In B. borealis the length is even greater 

 than the height, from the 9th dorsal back to the 7th caudal.] 



5. THE EPIPHYSES. The lengths of body given include the 

 epiphyses. On the 2nd or 3rd caudal the epiphyses, at midway 

 between the transverse process and the pedicle, are J inch thick. 

 [On the corresponding and neighbouring vertebrae of the B. 

 musculus, the epiphyses are 1 inch thick ; in the B. borealis 

 they are J inch thick.] In front of the last two lumbar, 

 the thickness has diminished to f inch ; at the first dorsal, to 

 about f . Backwards, along the caudal region, the epiphyses 

 remain undiminished in thickness to the 10th, after which the 

 bevelling of the edges, especially of the posterior epiphysis, 

 renders it not easy to measure the thickness, but back 

 even to the 17th caudal, the anterior epiphysis is still J inch 

 thick. After the 10th caudal, the posterior epiphysis is some- 

 what thinner than the anterior. After the 10th, the back of 

 the bodies becomes convex, the front remaining more nearly flat. 

 This is due to the bevelling off of the hinder edge of the pos- 

 terior epiphysis in the rapid tapering of the hinder vertebra? 

 of the tail. These measurements are taken at the unfinished 

 abrupt edges of the epiphyses, but 1 inch to 1J further in, 



