Fig. 1. Fossil fish of the genus Microdon, in the family Pycnodonts. (Agassiz, Vol. I. Tab. G. fig. 3.)
Fig. 2. Os Vomer of Gyrodus umbilicatus, from the Great Oolite of Durrheim, in Baden. (Agassiz.)
Fig. 3. Os Vomer of Pycnodus trigonus, from Stonesfield, Oxon. (Original.)
Plate 27d. V. I. p. 218, Note.
A. Teeth of a recent Shark, allied to fossil species.
Fig. 1. Anterior and Palatal Teeth of the Port Jackson Shark, (Cestracion Phillippi.) (Phillip.)
Fig. 2. Anterior cutting teeth of Port Jackson Shark, in the College of Surgeons, London. (Owen.)
Fig. 3. Flat tessellated tooth of the same. Nat. size. a. Outer articular facet, showing the tubular structure of the bony base. b. Punctate surface of the superficial enamel. (Owen.)
Fig. 4. Mesial, and inner articular facet of another large tooth of the same. a. Upper concave margin thinly covered with enamel, b. Lower bony margin without enamel, a, b. Bony base of the tooth exposed by removal of the Enamel. The surface is areolar, from the bending and blending together of the bony tubes, c, c'. Fractured edge of the marginal and superficial enamel. (Owen.)
Fig. 5. Another anterior cutting tooth, a. Smooth enamelled point, b. Minutely rugous and tuberculated base. In some of the cutting teeth both sides of the base are rugous. (Owen.)
B. Various forms of fossil Teeth, in the three sub-families of Sharks. (B. 1. to B. 13. Agassiz.)
Figs. 1—5. Teeth of fossil Sharks in the sub-family of Cestracionts. See V. I. p. 218.
