The specimen preserved comprises the entire crown of a single vomerine (?) tooth, 38 mm. in length by 14 mm. in diameter at base (pl. 21, fig. 6). The immediate tip had been partly worn away in life, but was acuminate. It is composed of a dense blackish material, with the exterior smooth, shining black. It has about 20 narrow flutings, nearly straight, running from the base to the tip, separating shallow grooves. A transverse section of the base shows a narrow pulp-cavity not more than 5 mm. in diameter which extends in about the same proportional width to beyond the middle of the tooth, and in all probability to near the apex. The cross-section of the tooth throughout is nearly or quite circular. A hemisection of the tooth was made near the middle, showing a structure most remarkably like that of _Mastodonsaurus_; so nearly alike, in fact, that there is no difference from the large figure given by Owen of a section of _Mastodonsaurus_ (502). The discovery of this tooth in the Kansas Coal Measures is of great interest, proving, as it does, the presence of true labyrinthodonts from a lower horizon than elsewhere recorded. The discovery of _Eobaphetes kansensis_ Moodie in the Carboniferous of Washington County (473) would seem to indicate another labyrinthodont. The tooth from Louisville was possibly not the first evidence of labyrinthodonts in North America, since the discovery by Marsh of _Eosaurus acadianus_ from the Coal Measures of Nova Scotia, possibly a member of the Stereospondylia, antedates this discovery 30 years. The specimen is preserved in the Museum at the University of Kansas. AMPHIBIAN FOOTPRINTS FROM THE COAL MEASURES. Footprints may be said to be fairly common in the Coal Measures of North America. Especial attention has been given to the classification of these objects by G. F. Matthew (408-413), Dawson (208-210) and others. Hay (317, pp. 538-553) has given a catalogue of all the species described from the Coal Measures of North America, to which the reader is referred for further information in regard to these interesting evidences of former animal activities. The writer has not been interested in the taxonomy of footprints, but has studied such as have come to his notice (465). A description of the species _Dromopus agilis_ Marsh (fig. 43) is given here, because there is a large slab in the University of Kansas Museum which has not been figured. Since the chief interest in the present contribution is morphology, footprints are thus scantily dealt with. Leidy (374), Dawson (207), Moodie (465, pl. LXIV, fig. 1) and others have given various brief descriptions of Coal Measures footprints, probably all of which are evidences of Amphibia which are otherwise unknown. =Dromopus agilis Marsh.= Marsh, Jour. Sci. (3), XLVIII, p. 82, pl. ii, fig. 3; pl. iii, fig. 3, 1894. Hay, Bull. U. S. Geol. Surv., No. 179, p. 543, 1902. Type: Specimen in the Yale University Museum.