_Barnegat City_ (female).—First thoracic: Spine vertical, pointed, about
as high as arch and centrum together. A moderately long process with
articular facet for tubercle of rib on side of neural arch; facet
elliptical and directed a little downward and forward. A smaller facet
for head of second rib on posterior upper edge of centrum.
Seventh thoracic: Metapophyses long, extending horizontally, straight
superiorly. A small articular facet on the outer side near the base,
directed downward; strongest on right side. A very small facet on
posterior upper edge of centrum, scarcely noticeable on right side.
Neural spine rather narrow at tip; superior margin straight.
Eighth thoracic: Metapophyses squared and thin. A distinct transverse
process on side of centrum about half as broad as the centrum is long,
and as long as centrum is broad; flattened, squared, and a little curved
backward and upward. Articular facet for rib elliptical and directed
obliquely backward. A broad, shallow groove across base of transverse
process, the anterior edge of which is emarginate proximally. Neural
spine as in seventh thoracic.
Ninth thoracic: Metapophyses squared. Transverse process similar to that
of eighth thoracic, but equal to centrum in length, little narrowed at
base, and directed outward; anterior edge convex, posterior concave;
articular facet occupying the posterior half of the distal edge. A very
shallow groove proximally.
_Newport_ (male).—First thoracic: Neural spine a little curved backward
and rounded at tip; much higher than length of arch and centrum together.
Articular facets as in Barnegat skeleton.
Seventh thoracic: Metapophyses similar in shape to those of Barnegat
skeleton but with a very distinct facet on side of arch, terminating a
process about as long as the greatest diameter of the facet; surface of
facet rugose. Below this process, on side of centrum, a very large, oval,
sessile facet, reaching forward nearly to the anterior face of the
centrum and upward to its superior edge. A very low, small swelling on
the posterior superior edge of centrum, probably indicating the point of
attachment of a cartilage connecting the head of the eighth rib. Neural
spine expanded at free end, and superior margin rounded.
Eighth thoracic: Metapophyses similar to those of Barnegat skeleton. A
distinct transverse process nearly as broad as the length of the centrum,
oblong or squared, flat, directed somewhat backward, but not upward.
Articular facet for rib not occupying whole of free end and only slightly
directed backward; anterior margin as in Barnegat skeleton. Neural spine
similar to that of seventh thoracic.
Ninth thoracic: Similar to that of Barnegat skeleton, but transverse
process longer than centrum and directed a little downward, articular
facet occupying less than posterior half of free margin; proximal groove
inconspicuous; anterior and posterior margins nearly straight.
_Charleston_ (female, jr.).—The centra of the thoracic, as well as the
lumbar, vertebræ in this individual present inferior median keels, and
more or less concave sides, which is not the case in the Barnegat and
Newport skeletons. This can not be due to immaturity, as in a still
younger individual, supposed to represent _Ziphius grebnitzkii_, the
thoracic vertebræ are rounded below. The neural spines of the thoracic
vertebræ are much less inclined backward in _semijunctus_ than in the
Newport and Barnegat skeletons, but this is doubtless connected with age,
as the younger series of vertebræ already mentioned exhibits the
peculiarity in a more marked degree. A similar modification dependent
upon age appears to affect _Hyperöodon_, as will be seen by comparing Van
Beneden and Gervais’ figures in the Osteography, plate 18.
First thoracic: Similar to that of Newport skeleton, but spine not higher
than arch alone. (A little abraded at tip, but probably undeveloped.)
Seventh thoracic: Metapophyses short (abraded), incompletely developed. A
distinct facet on side of same on an elongated process, as in Newport
skeleton, but no second larger one on side of centrum. No facet on
superior margin of centrum either anteriorly or posteriorly.
Eighth thoracic: Transverse process similar to that of Barnegat skeleton,
but anterior edge nearly straight; process about one-half as broad as
length of centrum. (Indications of immaturity.)