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Show 454 DR. J. MURIE ON SAIGA TARTARICA. [June 9, shortening of the body and transverse processes-in the latter being more bulbous terminally, and slightly upturned-in lengthening of the spine, which is uncleft- in a gradual increase of laminar arching- in separative distinctness of a metapophysial projection-in an alteration of the position of the transverse process to the pleurapo-physis, so that they begin to be superior and inferior to each other instead of antero-posterior-in diminution of the ventral keel, which, however, is more inflated posteriorly. At the sixth cervical, the inclination of the neck towards the shoulders is apparent. This vertebra altogether is shortened lengthwise and across ; but the elongation of the spinous and pleurapo-physial elements vastly increases the total depth. The changes observed in the fifth are here continued and augmented : for example, the neural spine is almost twice as long in the sixth ; the inferior mesial ridge of the body is reduced to a hardly perceptible linear elevation ; the transverse process and pleurapophysis have undergone such relations that the latter is absolutely posterior, its inclination is in that direction, and its breadth twice as great as in the preceding vertebra. The seventh vertebra, as usual, puts on characters which assimilate it to the dorsal series. The most notable of these is the great elongation and backward direction of the spinous process ; next, the total absence of pleurapophysis and foramina for the vertebral arteries ; and lastly, the presence of a small costal facet. Transition to dorsal vertebrae, though manifest in the last cervical, is yet somewhat abrupt, the first dorsal being altogether larger, with proportionally an enormously developed spine Moreover its body, as commencing the dorsal region ventrally, is set at an obtuse angle to those of the neck, the plane of the former being directed upwards and backwards, the latter upwards and forwards. The pattern of the bodies of the dorsal vertebrae is twofold; but they run into each other; viz. as far as the 5th or 6th they are broadish and convex inferiorly, thence to the lumbar region laterally compressed and slightly carinate. The laminae throughout correspond to the length and strength of the spinous process. Where this is long and stout, the laminar arch is more acute, and, inversely, lower and arciform as the neurapophysis shortens. The spine of the first dorsal is very slightly shorter, and tapers more than the 2nd and 3rd, and equals the 4th in length, which latter has a truncate tip. These four spines slant well backwards. At the 8th or 9th vertebra an alteration is apparent, and, from the long spatular shape directed posteriorly, the spines become short, more erect, with an anterior terminal elongation, aud at the last dorsal the change to the lumbar type is complete. That which appertains as a marked feature of the lumbar vertebrae is the length of the transverse processes; at least, this is especially so in the penultimate and two preceding ones. They are thin, relatively narrow, excepting the first, and each terminates in a hastate manner. The first and last are shorter than the intervening |