1859 R. Owen in XVII. 150/1 On the inferior surface the palato-nasal, the pterygo-sphenoid and the pterygo-malar vacuities.
1893 (Royal Soc.) B. 183 325 There are..upon the under-side of the head, the comma-shaped vacuities in front like those of Lizards, the single median pterygo-sphenoid vacuity, [etc.].