392 HARRIS HAWTHORNE WILDER ON 
spicuously amphicoelous. In the recent state 
. . . : . int. 2ygapophy sis. 
these depressions are filled in with portions of the : 
original notochord which become restricted to 
these intervertebral segments by the develop- 
ment of the osseous vertebrae. Corresponding to ry | 
yt 
the shape of the space included by two approxi- 
mated ends of vertebrae, these notochordal seg- 
> Socket for 
pace nae 
Cartilage 
ments are in the shape of two cones placed base 
to base, the place where the two bases meet being 
the line of separation between the two vertebrae ae , 
lost Zygapophysis , Newrapophyses 
involved. pee it oh ried 
The neural arch is much flattened dorsally, ty, 
and its sides, the neural laminae, become so much erica 
obscured by fusions with the elements of the Fig. 2. 16th vertebra; ventral aspect. X 3. 
transverse process that they are seen distinctly 
only when the vertebra is viewed from one end. The main bulk of the arch consists of 
a flat neural plate, which in a dorsal view of the vertebra nearly conceals the rest. 
This plate is approximately a rectangle with sides a little incurved. Anteriorly its cor- 
ners become prolonged into a pair of rounded anterior zygapophyses, and posteriorly it 
develops a pair of somewhat similarly 
Fossa. 
gi ta shaped posterior zygapophyses, between 
Gnt. 2ygebobh = : Se ZB Neurapoph. 
which extends a short, median process. 
Paula r5serent As the posterior zygapophyses of each 
Socket for Pheurape- 
Gt erly physial Cartilage vertebra overlap the anterior ones of 
of Centrum. ) 
the next succeeding, the articular sur- 
v7 * Post. vertebral 
Sheath for plewrape- fossa. 
magia cacelase faces of the former lie upon the ventral, 
Wig. 8. 16th wertepene Wet dateraliaspeotemcet: and those of the latter upon the dorsal 
aspect. At the blunt posterior point of 
the posteriorly directed median process, there is a small cup-shaped depression filled, in 
the recent state, with a nodule of cartilage which forms the tip of the neural spine, the 
osseous continuation of which extends along the median line of the neural plate, becom- 
ing obsolete anteriorly. 
The term “ transverse process” is a convenient name by which to distinguish certain 
composite and irregular masses placed upon either side of the centrum and bearing the 
proximally forked ribs. Each transverse process consists essentially of two cartilaginous 
rods, dorsal and ventral, encased in an irregular bony mass. Of these two rods, the dor- 
sal one, the diapophysis, proceeds from the side of the neural arch, while the ventral 
