_Newport_ (male).—The seventh cervical vertebra presents a conical
metapophysis, which on the first thoracic vertebra forms of a rather
thick, long, declining process ending in a facet for the tubercle of the
first rib. This metapophysis maintains nearly the same form as far as the
sixth thoracic vertebra, but on the third thoracic a mammiliform process
makes its appearance on the anterior margin near the tip, and becomes
more prominent on each succeeding vertebra. On the seventh thoracic it
becomes larger, thin, and upright, and widely separated from the
articular facet for the tubercle of the rib. On the centrum of this
vertebra lower down is a second much larger rugose articular facet. On
the eighth thoracic vertebra the upper articular process disappears
altogether and is replaced by a transverse process on a lower level, with
a facet at the free end for the rib. On the ninth thoracic the transverse
processes are larger and nearly straight. They are longer on the first
lumbar and incline a little forward. Those of the succeeding vertebræ are
similar, but decrease gradually in length, while somewhat increasing in
breadth. They are last traceable on the ninth caudal. On the eighth
caudal they are perforated by a foramen.
All the vertebræ from the first cervical backward have neural spines as
far as and including the eleventh caudal. The spine on the first thoracic
is rather short, narrow and pointed. These spines increase in height in
succeeding vertebræ as far as the sixth lumbar; at the same time the
breadth increases antero-posteriorly and the tip becomes expanded. The
spines are nearly equally high on all the succeeding lumbars, but begin
to decrease on the caudals and disappear altogether on the eleventh
caudal.
The anterior zygapophyses and metapophyses maintain a nearly constant
position close to the top of the centra throughout the column, from the
seventh thoracic backward, and are vertical, thin, and oblong, squared or
rounded. They begin to decrease in size noticeably on the first caudal,
and on the seventh caudal are mere swellings at the sides of the nearly
horizontal plate from which the neural spine springs. They are traceable
as far as the twelfth caudal.
A ridge appears on the side of the neural arch near its base on the fifth
caudal and is stronger and very marked on those following, to the ninth
caudal. A ridge unites the anterior and posterior facets for the chevrons
on the ninth and succeeding caudals.
_Barnegat City_ (female).—Unlike the Newport skeleton, there are no
neural spines on the fifth, sixth, and seventh cervicals. The spine on
the first thoracic vertebra is quite short and sharp, and on the second,
third, and fourth thoracics also is rather pointed, though of increased
length. There is no metapophysis on the seventh cervical.
On the seventh thoracic the facet for the tubercle of the rib, instead of
being very prominent, becomes inconspicuous. The metapophysis is flat and
squared, and there is no lower facet on the side of the centrum. On the
eighth thoracic the metapophysis is thin, squared, and vertical, and a
well-formed transverse process appears on the side of the centrum. The
transverse processes of the ninth thoracic are a little curved backward,
and on the first lumbar and succeeding vertebræ bent forward. These
processes are less tapering on all the lumbars than in the Newport
skeleton. They disappear on the eighth caudal. None is perforated.
The longest neural spine is on the sixth lumbar, and on all the lumbars
both the anterior and posterior edges are somewhat convex. Hence their
shape is rather different from those of the Newport skeleton, in which
the anterior margins are somewhat concave. The tips of the spines are
rather suddenly expanded. The spines of the caudals are rather more
expanded at the tip and more inclined backward than in the Newport
skeleton. They disappear on the eleventh caudal.
The horizontal plate joining the metapophyses is noticeable on the fifth
caudal. The ridge on the side of the neural arch is first noticeable on
the fourth caudal and is very strong on the fifth, sixth, and seventh.
The metapophyses are last traceable on the twelfth caudal.
_Charleston_ (female, jr.).—This skeleton resembles the Newport one as
regards the facets for the articulation of the tubercles of the ribs,
except that the seventh thoracic resembles the sixth and has no lower
facet on the side of the centrum. The transverse processes of the ninth
thoracic are rather strongly curved backward, while those on the last
thoracic and first lumbar are nearly straight. On succeeding vertebræ
they are inclined forward. They are last traceable on the eighth or ninth
caudal (vertebra 35 or 36). None is perforated by a foramen.
Though the vertebræ are defective, there appear to have been no neural
spines on the fourth to the seventh cervicals, inclusive. The spine on
the first thoracic is short, and on the first to the fourth is pointed.
The spine disappears on the tenth caudal (vertebra 37).
The metapophyses assume the vertical position on the eighth thoracic. The
last of these processes is barely traceable on the tenth caudal (vertebra
37). The ridge on the side of the neural arch is well marked on the fifth
to the ninth caudals, inclusive. On the seventh caudal (vertebra 34) the
anterior and posterior facets for the chevrons are united on the right
side, and on the eighth caudal and succeeding vertebræ on both sides.