On Some Mammalian Teeth from the Wealden of Hastings

Abstract

S ince the late Prof. Marsh's discovery of mammalian teeth and bones in the coarse grits of the Laramie Formation in Wyoming (U.S.A.), Mr. Charles Dawson, F.G.S., has persistently searched for similar fossils in deposits of the same nature in the Wealden formation of Sussex. These beds consist chiefly of coarse quartz-grains mingled with teeth of fishes and fragments of bones, and were originally noticed by Mantell under the name of ‘Tilgate Grit.’ According to Mr. Dawson's observations, however, they form only small lenticular deposits, and occur at several horizons in the Wealden Series. The first result of this search was the discovery of a molar of Plagiaulax , which I described and named Pl. dawsoni in 1891 More recent work, in which Mr. Dawson has been helped by Messrs. P. Teilhard de Chardin and Félix Pelletier, has led to the finding of three additional specimens—two probably belonging to Plagiaulax itself, the third to a distinct though related genus. The first-described tooth was met with in the Wadhurst Clay behind St. Leonards, while the three new teeth were obtained from the Ashdown Sands of the Fairlight Cliffs near Hastings. The two new molars which seem to belong to Plagiaulax are unfortunately very imperfect. In one the crown is seen to be closely similar to that of the original tooth of Pl. dawsoni . In the second specimen most of the crown has decayed, but the two divergent roots are well displayed, the one somewhat stouter than the other. The third specimen is especially