. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. Superior pharyngeal bones and teeth (Seams'). lamella, slightly curved like a finger-nail, is the singular form of tooth in an extinct genus of fishes, which I have thence called Petalodns. Sometimes the incisive form of tooth is notched in the middle of the cutting edge, as in Sargits unimaculatus. Sometimes the edge of the crown is trilobate (Aplodactyhts, fig. 566.). Fig. Front teeth of Aplodactijlus. Sometimes it is made quinquelobate by a double notch on each side of the large middle lobe (Boops). In the formi
. The cyclopædia of anatomy and physiology. Anatomy; Physiology; Zoology. Superior pharyngeal bones and teeth (Seams'). lamella, slightly curved like a finger-nail, is the singular form of tooth in an extinct genus of fishes, which I have thence called Petalodns. Sometimes the incisive form of tooth is notched in the middle of the cutting edge, as in Sargits unimaculatus. Sometimes the edge of the crown is trilobate (Aplodactyhts, fig. 566.). Fig. Front teeth of Aplodactijlus. Sometimes it is made quinquelobate by a double notch on each side of the large middle lobe (Boops). In the formidable Sea-pike t Odontography, pi. 38, /?</. 2; and art. PISCES, Vol. 111. p (J80,/</. 517. (SpkyroEna Barracuda') the crown of each tooth, large and small, is produced into a compressed and sharp point, and resembles a lancet. Sometimes the edges of such lancet- shaped teeth are finely serrated, as in Priodon, and the great Sharks of the genus Carc/iarias, the fossil teeth of which indicate a species (Cnrch. Megalodon) sixty or seventy feet in length. The lancetted form is exchanged for the stronger spear-shaped tooth in the Sharks of the genus Lamna; and in the allied great ex- tinct Otodus, as in the small Porbeagle, simi- larly shaped, but stronger, piercing and cut- ting teeth were complicated by one or more accessory compressed cusps on each side their base, like the Malay crease. With respect to situation, the teeth, in Sharks and Rays, are limited to the bones (maxillary and mandibular), which form the anterior aperture of the mouth : in the Carp and other Cyprinoids the teeth are confined to the bones (pharyngeal and basi-occipital) which circumscribe the posterior aperture of the mouth. The Wrasses (Labrus] and the Parrot-fishes (Scants) have teeth on the pre-maxillary and pre-mandibular, as well as on the upper and lower pharyngeals ; both the anterior and posterior apertures of the mouth being thus provided with instruments for seizing, dividing, or comminuti
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