Figure 1, 1a. Outer and oral aspects of the imperfect dentary bone of Sarcolestes Leedsi, from the Oxford Clay of Peterborough. 2/3 nat size. s = symphysis. Figure 1b. A single tooth of the former. 3/1 nat size. Figure 2, 2a. Outer aspect and quadratic cavity of the hinder region of the same jaw. 2/3 nat size. Figure 3. A single tooth of Priodontognathus Phillipsi, 3/1 nat size, shown for purposes of comparison. Specimen in the Woodwardian Museum, Cambridge.