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Show 674 MR. F. E. BEDDARD ON BASSARICYON ALLENI. [June 19, large as in Bassaricyon. The third, fourth, and fifth cervicals have in Bassaricyon double hypapophyses; these are absent in Cercoleptes. In the dorsal vertebrae the spine slopes backwards in the first ten ; the change is so marked (as indeed it always is in this group) that the spine of the eleventh is in absolute contact with that of the tenth. Cercoleptes is similar in this point of structure. In the caudal series the first four vertebrae bear V-shaped chevrons which are not ankylosed to the centra. After this the two equivalent processes widely diverge with each other and are firmly ankylosed. In Cercoleptes the first five chevrons form complete canals and are detachable from the vertebrae ; that of the sixth is composed of two pieces which nearly meet but are ankylosed with the centrum. The rest are divergent and do not enclose a canal; they are also ankylosed. Since the tail of Cercoleptes is prehensile while that of Bassaricyon is not, it is not surprising to find that the transverse and other processes of the caudal vertebrae are more marked and continue marked to nearer the end of the tail in that form than in Bassaricyon. As already mentioned, there are thirteen pairs of ribs. Of these the first nine are attached to the sternum. The capitula of the first ten are intercentral in position; those of the rest have moved back on to the centrum of their vertebra. A distinct tuberculum is not visible after the tenth. In Cercoleptes there are fourteen pairs of ribs ; the additional one in that animal differs from those which precede it in the fact that it is attached not to the centrum of its vertebra but to an apparent transverse process which, however,.is not ankylosed to the centrum and, moreover, is directed backwards while those of the succeeding lumbar vertebrae are directed forwards. In Bassaricyon the transverse processes of this vertebra (which certainly have not ribs, as the skeleton was most corefully preserved) have the same direction as those which follow, though they are rather smaller. The first eleven ribs of Cercoleptes have capitula which are intercentral in articulation. This eleventh rib is the last which possesses a distinct tuberculum. Only nine, as in Bassaricyon, reach the sternum. In both genera the sternum consists of nine pieces ; and in both the last but one is much smaller than those on either side of it. The shoulder-girdle is very like that of Cercoleptes ; the outline is precisely so, but the ridges, on the inner surface of which there are four in Cercoleptes, are reduced to two. I saw no clavicle, which if present must be very minute, as it is in Cercoleptes. As to the remaining parts of the skeleton, I have noted no differences from Cercoleptes. It may be useful to append to tbe foregoing notes upon the structure of Bassaricyon a condensed definition of the genus. It should certainly be referred to the Procyonidae, as has indeed been the opinion of all recent writers. |