16), extending between the fenestra ovalis and the tympanic membrane or drum, consists of (I) the long and slen der columella, a straight, ossified rod which fits with a disk into the fenestra r; t st ovalis; it is homologous with the stapes (m.st.), although not stirrupshaped; (2) the extra-columellar mass.
No batrachian is known to possess an ossified azygous supraoccipital.
A membranous, or ossified, tube which rises from a pneumatic foramen in the os articulare, on the median side of the articulation, and passes upwards between the quadrate and lateral occipital bone, opening into the cavity of the middle ear.
Later those pads fuse with the anterior end of the centrum of the vertebra to which they belong; where the vertebral column is rendered inflexible, the disks are ossified with the centra and all trace of them is lost.
" It was a necessity that Judaism should incrust itself in this manner; without those hard and ossified forms the preservation of its essential elements would have proved impossible.
Nasal bones large and stout, co-ossified, and standing out freely above the premaxillae, from which they are separated by a deep and wide fissure; the latter small, generally not meeting in the middle line in front, often rudimentary.
The scutes or dermal portions of the scales are more or less ossified, especially on the back, and form the characteristic dermal armour.
The ribs are eighteen or nineteen in number on each side, flattened, and united to the sternum by short, stout, tolerably well ossified sternal ribs.
The bones which bear the two occipital condyles have given rise to much discussion, and the definition given by Huxley in the previous edition - "two occipital condyles, the basi-occipital region of the skull either very incompletely or not at all ossified" - requires revision.
The fact remains, however, that some if not all of the stegocephalous batrachians have an ossified basi-occipital.
Even the inferior arches or chevrons of the tail of salamanders are continuously ossified with the centra.
Either to the vertebra anterior (procoelous type) or posterior (opisthocoelous type) to it, if not remaining as an independent, intervertebral, ossified sphere, as we sometimes find in specimens of Pelobatidae.
The pectoral girdle of the Stegocephalia is, of course, only known from the ossified elements, the identification of which has given rise to some diversity of opinion.
The pelvic arch of some of the Stegocephalia contained a well ossified pubic element, whilst in all other batrachians only the ilium, or the ilium and the ischium are ossified.
Bb l, Ossified second Gl, Glottis.
The short feet of the penguins are an adaptation.