Parker has described vestiges of the corresponding cartilages in the Apteryx (Phil.
In the lower jaw of most of the Ecaudata the symphysial cartilages ossify separately from the dentary bones, forming the so-called mento-meckelian bones; but these symphysial bones, so distinct in the frog, are less so in the Hylidae and Bufonidae, almost indistinguishable in the Pelobatidae and Discoglossidae, whilst in the Aglossa they do not exist any more than in the other orders of batrachians.
The long bones of the limbs consist of an axis of cartilage; the extremities of the cartilages frequently undergo calcification and are thus converted into epiphyses.
The skeleton is cartilaginous, and the skull is remarkable for the very elongate suspensorium of the lower jaw; the tail remains in the notochordal condition, no cartilages being formed in this organ, which is destined to disappear with the gills.
Towards the end of the body both neural and haemal arches are continued into forked radial cartilages, which support a median fin.