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Show 1895.] LORIUS FLA.VOPALLIATUS AND PSITTACUS ERITHACUS. 319 physes (pz) look dorsad, mesiad, and almost slightly postaxiad, and so contrast strongly with those of the fifth vertebra. As they do not extend so much forward, the anterior ends of the lateral arterial canal (ac) are visible when the vertebra is viewed dorsally. The hypapophysis has disappeared, but the structure of the pleurapophysial lamella is otherwise much as in the fifth vertebra, save that the foramen (/) formed by its superior postaxial process is larger. In P. erithacus the conditions are similar, except that the neural spine is not so obsolete. In this species the sixth vertebra is the first and only one to have a lateral foramen (/) formed by the process of the pleurapophysial lamella. The catapophyses (c) are rather more marked than in the fifth vertebra. In both species the metapophyses (m) are prominent. The seventh vertebra of L. fiavopedliatus is very like the sixth, and the same may be said in the case of P. erithacus, except that in the latter species there is no lateral foramen and the pleurapophysial processes (st) are longer. In both, the catapophyses (c) are more developed than in the preceding vertebra and project preaxiad as well as ventrad. In both, the metapophyses (ni) are as well developed as before. The eighth vertebra has the catapophyses (c) again more prominent and approximated, and they are at their maximum. In L. fiavopalliatus the hyperapophyses (hp) have almost disappeared, and hardly less so in P. erithacus. In both they have again receded and stand upon the postzygapophyses. In the ninth vertebra the hypapophysis (h) suddenly reappears and is of large size in both species. The neural spine also reappears of considerable size, and is quadrate in shape in P. erithacus, but it is only represented by a very low and delicate ridge in L. fiavopalliatus. In both species the postzygapophyses are shorter and less diverging than in the eighth vertebra. In L. fiavopedliatus the lateral1 foramen (f) has become slightly smaller. In both species the metapophyses (m) are rather more developed and are indeed at their maximum. In L. fiavopalliatus there are still hyperapophyses (hp) on the postzygapophyses. In the tenth vertebra the lateral foramen disappears in L.fiavopalliatus, and the postaxial margin of the pleurapophysial lamella (pi) develops two processes projecting postaxiad and slightly ventrad. The neural spine (ii) for the first time reappears as a distinct, though smaller pointed process. The postzygapophyses (ptz) are smaller than in the preceding vertebra, only projecting about as much backwards as the prezygapophyses do forwards. The hypapophysis (h) is much as in the ninth vertebra. In P. erithacus it is rather smaller than in the preceding vertebra, slightly bifurcating at its distal end, and the neural spine is certainly smaller. In both species the metapophyses (m) are rather smaller. The eleventh vertebra in L. fiavopalliatus bears a distinct, quadrate 1 Not the canal enclosed by the pleurapophysial lamella as a whole (that persists on into the eleventh vertebra in both), but only that enclosed by the delicate upper postaxiad process of that lamella. |