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Show 474 DR. J. V. HAAST ON ZIPHIUS NOV^-ZEALANDI^. [June 6, still the flattened appearance of the first, but in a lesser degree, which they assume all nearly the same shape, the upper portion below the articulations or articulation having a prismoid form, which is most pronounced in the middle of the ribs, where they are also the most constricted, the edge being on the inner side; they then widen and flatten to their lower extremity. The second to the seventh rib inclusive have, like the first, two • articulations ; a distinct capitular process for articulation with the vertebra in front, and an excavated articular surface slightly raised round the edges, into which the transverse process fits. The eighth and ninth ribs have only one excavated surface, articulating with the end of the transverse process. The greatest length of each rib, measured in a straight line, is:- ft. in. 1 9i 2 6| 2 10^ 3 Oi 3 2 3 3J 2 Hi 2 5| Sternum. In the form of the sternum Ziphius nova-zealandia shows a well-marked difference from Z. australis of Buenos Aires. It consists of five distinct segments, of which the first is the largest, having a greatest length of 14| inches, with a greatest breadth of 12| inches. The second, third, and fourth segments gradually diminish in both dimensions until the fifth, which is the narrowest but longer than the three preceding ones. The dimensions of the fifth are 7f inches in length with a breadth of 6 inches. The first, which possesses a shallow keel in its upper portion, has a deep notch above it, and another in the centre of its basal portion. Similar fossae exist in each of the succeeding segments, by which four median fenestrse are formed, gradually dimininishing in size, having their largest diameter in a vertical direction. There are six articular surfaces on each side for the sternal ribs-the first near the upper portion of the first segment, the second at the junction of the first and second, the third at the junction of the second aud third, the fourth at the junction of the third and fourth, the fifth at the junction of the fourth and fifth segments, and the last at the posterior ends of the two narrow processes by which the fifth segment terminates. The entire length of the sternum in a straight line is 3 feet 1 inch. A comparison with the sternum of Ziphius australis shows a great difference in the form of the segments of the fenestrae; and, as it appears to me, when mature, this species would only have four segments instead of five, thus agreeing with Berardius arnouxi. First... Second Third . Fourth. Fifth . Sixth . Seventh Eighth. Ninth |