Note on subfossil teeth of Equus zebra L. from Orange free State

Some time ago Dr. L. D. Brongersma, curator of the Leiden Museum, entrusted me for examination some subfossil equine teeth, received from Mr. H. van Hoepen, who had found them between Glen and Mazelspoort, in Orange Free State. The teeth proved to belong all to one and the same individual, and to constitute the entire upper premolar-molar-series of the right side, almost undamaged. The importance of this find is evident, as most of the fossil or subfossil equine species from S. Africa are based on isolated teeth. An inner view of our specimen is given in pl. VI lower figure, the crown surfaces are represented in the upper figure of the same plate. It can be seen, that the P4 is the longest tooth, its height is 72 mm. The mesostyle is prominent, and especially marked off anteriorly. The parastyle is well defined in P3 and P4, less so in the molars, especially in M1. Between these styles the ectoloph is almost straight in the premolars, and slightly concave in the molars. The posterior half of the ectoloph, however, is more concave in the premolars than in the molars, the latter having a less developed metastyle. The enamel pattern is comparatively simple, the pli protoloph 1) and the pli hypostyle are hardly or not developed. A slight trace of a pli prefossette is found in P4 only. A small pli postfossette is seen in the premolars, in the molars it is hardly indicated. The pli protoconule is present in all the teeth, though shorter in the molars than in the premolars. The groove between protocone and hypocone is sharply pointed towards the outer side, a pli caballin is absent. The protocones are remarkable for the very slight development of their anterior lobe; they increase in length from before backward. First I compared the subfossil teeth with those of Equus quagga. Of