. Bulletin. Natural history; Natuurlijke historie. 72 PEABODY MUSEUM BULLETIN 38 septum nasi is present only as a dorsal band of bone that curves upward as it passes forward and then, at the very tip of the nasal cavity, curves downward again to merge with the anterior nasal wall of each side. The anteromedial nasal chambers of each side are thus not completely separated by the bony septum nasi, although probably in life a ventral cartilaginous extension of the septum had this function. This is a problem of some importance in determining the homology of the nasal septum (see "Embryologica
. Bulletin. Natural history; Natuurlijke historie. 72 PEABODY MUSEUM BULLETIN 38 septum nasi is present only as a dorsal band of bone that curves upward as it passes forward and then, at the very tip of the nasal cavity, curves downward again to merge with the anterior nasal wall of each side. The anteromedial nasal chambers of each side are thus not completely separated by the bony septum nasi, although probably in life a ventral cartilaginous extension of the septum had this function. This is a problem of some importance in determining the homology of the nasal septum (see "Embryological Analysis"). As far as we can see no major foramina pierce the sides of the septum nasi. Posteriorly the septum nasi is completely merged with the anterior portion of the braincase that overlies the palatoquadrate. The triangular tip of the palate projects forward to lie partly under the nasal chambers and presumably in life they were continuous with a cartilaginous solum nasi. Along the lateral margins of the tip of the palate on each side there is a large horizontal longitudinal groove (Fig. 29B, gr subn v; Fig. 78) passing backward under the nasal capsule into the orbital cavity. The dorsal rim of this groove was probably continuous with the solum nasi. This groove almost certainly carried a large vein backward from the nasal region toward the suborbital sinus, but there are also several canal openings that probably carried nerves into this groove. The most anterior of these may have served for the exit into the subnasal region of the palatal branch of the facial nerve (Fig. 29B, / pal VII). The canal for the olfactory tract enters the nasal cavity in the posterior part of the internasal septum at a deep recess (Fig. 29A; Fig. 78) just medial to the proximal corner of the postnasal wall. The olfactory tract canal is divided into two portions by a vertical septum. The principal bony portion of the postnasal wall is a stout ventral bar given off from the anterior portion
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