"Skull of Polyodon. n, nasal cavity; sq, squamosal; mh, hyomandibular; sy, symplectic; pa, palate-pterygold; m, Meckelian cartiledge; mx, maxillary; d, dentary; h, hyoid; op, operculum; br, branchiostergal; s.cl, supraclavicular; p.cl, postclavicular; cl, clavicle; i.cl, infraclavicular." — Encyclopedia Britannica, 1893

Polyodon

"Skull of Polyodon. n, nasal cavity; sq, squamosal; mh, hyomandibular; sy, symplectic; pa, palate-pterygold;…