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Show 482 DR. J. V. HAAST ON MESOPLODON FLOWERI. [June 6, Mesoplodonfloweri thus agrees in these particulars with M. sower-biensis. Cervical Vertebra. Measured along the lower side of their main bodies, the seven cervical vertebrae have a total length of 5*75 inches. Of them, the atlas, second, and third vertebrae are united into one large triangular bone 8 inches broad and 6*10 inches high (see no. 16). Only their lower processes, of which those of the second are the largest, are free. The third vertetebra has two distinct transverse processes on each side, of which the higher one (diapophysis) is a thin bone, with its termination pointing downwards. The next four vertebrae are all free ; and if we take into consideration that the skeleton under review belonged to a fullv adult animal, there is no doubt that no further change in their relations to each other would have taken place. The upper as well as the inferior transverse processes become gradually smaller as we advance towards the thoracic region. In the fourth vertebra the inferior transverse process has still a horizontal direction ; in the fifth it assumes a downward slope, which is continued to the seventh, where it consists only of a small tubercle. Above it, on the side of the body of this vertebra, is the articular surface for the head of the first rib. The fourth vertebra had evidently a small spinous process, which doubtless was broken off in cleaning it; in the fifth the spinous process is 1*05 inch, in the sixth 1*53 inch, and in the seventh 2 inches high, all leaning a little forwards. The bodies of the last four vertebrae are broader than they are high. M. floweri therefore stands so far alone in regard to the arrangement of the cervical vertebrae, as no other Ziphiod Whale, so far as I am aware, has the first three cervical vertebrae ankylosed and each of the next four perfectly free. Thoracic Vertebra. The species under review possesses ten, of which the bodies are all flattened from top to bottom and become gradually of larger dimensions, the body of the first being 1*12 inch, and the tenth 4*20 inches in postero-anterior length. The spinous process of the first is pointed and stands slightly forwards ; that of the second stands nearly vertical, after which in the remaining eight vertebrae it gradually slopes more and more backward and becomes higher and broader. This process in the second aDd third has rather a rounded apex, after which it becomes more truncated in the rest. The height of the spine of the first thoracic vertebra is 4*25 inches, of the tenth 9 inches. The articulation for the head of the second rib is situated at the posterior end of the first vertebra, low, at the base of the arch ; it rises gradually in the two next, so that in the third vertebra this articulation is placed some distance above that base, a position which it maintains in the fourth, fifth, and sixth, after which it disappears, the following ribs having only one articulation. The transverse process, which springs from both sides of the arch, |
