ON THE GREENLAND RIGHT-WHALE. 125 



of very broad but low osseous knobs; in the seventh caudal vertebra the arch can hardly be said to 

 have a spinous process in the mesial line of its upper surface. 



The eighth, ninth, and tenth caudal vertebrae belong to those vrhich are most easily distin- 

 guishable in the entire vertebral column, the arch having disappeared with the spinous process ; 

 but the cavity of the spinal cord is nevertheless still perceptible as a deep groove at the bottom 

 of which the two lateral canals are observed to open. 



The series of those vertebrae in which every trace of the arch has disappeared with the pro- 

 cesses, and which accordingly only consist of the vertebral bodies, begins in the Greenland whale 

 with the eleventh caudal vertebra. Gradually diminishing in circumference, from having at first 

 circular outhiies, when divided transversely, and their foremost and hindmost surfaces convex 

 (from the eighth to the eleventh), they become, as usual in the whales, cuboid with rounded 

 corners, nor is their breadth greatly superior to their height, contrary to what is the case with 

 those of the rorquals. As distinguishing marks from the posterior caudal vertebrae of the rorquals, 

 we may still mention, that their four corners, though tolerably obtuse, still project pretty much in 

 the form of roundish knobs, and that the longitudinal groove of the aorta is exceedingly slightly 

 marked, while the transverse groove for its lateral branches is more distinctly traceable on the 

 superior as well as on the inferior surface. Both these grooves, as usual, disappear in the canals 

 of these lateral branches of the aorta. 



In our forty-four feet long skeleton, of which the first caudal vertebra was thirteen and a 

 quarter inches broad, twelve and a quarter inches high, and about seven and three quarter inches 

 long J the seventh had still a breadth of eleven inches, a height of eleven inches, and a length of 

 about six and a half inches, but the fourteenth was only five inches eight lines broad, five inches 

 high, and about three and a quarter inches long ; the twenty-first, only two inches long, two and 

 a half inches broad, and two and a quarter inches high. The last caudal vertebra was, indeed, 

 in this instance, three and a half inches long; but this extraordinary development of the last 

 caudal vertebra of this specimen, we must consider as something quite accidental, as it was 

 observed neither in the twenty-two feet long skeleton, nor in the newborn young one and the 

 foetus. 



Of the inferior arches, or chevron bones, all those which we found in our two large skeletons, 

 or the ten foremost ones, consisted each of a single bone, but in the foetus the four suceeding 

 ones consisted of two separate cartilages. They are attached to the two vertebral bodies between 

 which they are placed in the usual manner, nor do they differ much from those of the rorquals, 

 not even in their form ; most different in this respect is the very foremost one, which, together 

 with the second, is shown in the woodcut at p. 123. The first (between the thirty-third and 

 thirty-fourth vertebrae) is smallei- than the next following ; but after this they decrease uniformly 

 in a backward direction, and it is especially the spine or ridge developed from their ankylosed 

 ends that becomes continually lower, and disappears entirely in the hindmost ones. 



The description given above of the vertebral column of the Greenland whale will have proved 

 sufficiently, that it is only in the cervical and the anterior dorsal vertebrae that we can point 

 out certain characters for this species. All the rest of the vertebrae, as well as the ribs, are 

 according to their natural order of succession in every essential point subjected to the same alter- 

 ations of form, as in other whalebone-whales, and, though it is easy, in almost every case, to point 

 out immediately to what region of the vertebral column any given vertebra of a large Cetacean 

 belongs, we shall, perhaps, often find it difficult to decide whether such a vertebra has 



