430

400

The neural spine is represented by a pointed ligamentous surface above the fore
border of the arch ; behind this rises the pair of low obtuse processes subsiding into
the hyperapophyses above the postzygapophyses.

As the neural roof subsides behind the part between the bases of the parial, quasi-
neural spines, their connecting-bar is so indicated. The hind part of each spine extends,
subsiding to the hyperapophyses.

TWELFTH VERTEBRA ( 1/2 natural size).

* Insert diagrams*

The twelfth cervical is chiefly distinguished by the nearer proximity ot one another
of the hypapophyses, the extremities of which, in a direct hind view (fig. 16, hy),
appear below the divisions of the postaxial surface, pc, not at its sides as in Struthio 1.
The transverse diameter of the postaxial part of the neural arch, taken outside the
pedicles, is one fourth less than the same diameter of the preaxial part. The riblet
(fig. 15, pl), though longer than in the six or seven preceding cervicals, is relatively
shorter than in the fourth (fig. 12, pl). The neural arch attains its greatest length in
the twelfth vertebra. The connecting bar (fig. 16, b) of the parial neural spines is
slightly raised, and is better defined before and behind by the rough pits for the
elastic ligaments than in some of the antecedent cervicals. The breadth of the neural
platform across the postzygapophyses is relatively greater, in a small degree, than in
the antecedent cervicals ; yet their articular surfaces (fig. 15, pz) remain longer in
proportion to their breadth. The perforation of the interzygapophysial bar continues.

Ib. loc. cit. p. 493, fig. 30,c.