| OCR Text |
Show 120 EflTHONYX MITICULUS, 8p. tlOV. Represented by portions of mandibular rami of three or four individuals of nmch smaller size than any of those referred to the species already described. There are represented two premolars and three molars; other teeth are lost. The molars differ from those of the three species named in lacking the notch or groove on the inner side of the anterior rriaugle of the crown, which constitutes it a V in those species, giving the worn surface a more simply sigmoid form ; the anterior portion is, moreover, not materially more elevated thau the posterior. The lust molar has a large heel, an inner and two anterior tubercles when little worn. The premolars preserved are each two-rooted, the last is like the correponding one in E. acer, the penultimate without heel or inner tubercles. Measurements. M Length of three true molars, ( No. 1) 0120 Length of two last premolars, ( No. 2) 0064 Length of first true molar, ( No. 1) 0040 Width of first true molar, ( No. 1) 0030 Depth of ramus at first true molar, ( No. 1) 0080 The worn surfaces of the first and second true molars are much like those of the corresponding teeth of Menolhcrium, Cope. That genus differs in the reduced form of the last inferior molar and in the premolars. MKNISCOTIIEKIUM CHAMEXSE, gen. et sp. now Char. gen.- Molars three, with two continuous external crescents and two internal tubercles, except on the posterior, where there is but one, the anterior conic tubercle. The posterior tubercles on the other molars crescintoid in section. A well- developed crescent between the anterior tnbercle aud anterior crescent, and an oblique crest extending from the latter to the adjacent horn of the posterior inner tubercle. Two external crescents on the last premolar. This genus presents a curious combination in the structure of its molars of the character of Palceosyops, Hyopotamus, and Jlipposyus. It is exceptional among the ungulates of the same fauna iu the number of crescents of the molars. Char. speci/*.- Last molar with the oblique inner posterior crest terminating at the posterior margin of the crown. Prominent external ribs at the point of connection of the external crescents of the crown. No cinguia; enamel entirely smooth. Measurements, M. Length ( externally) of last four molars 029 Length of true molars 022 Length of penultimate .009 Width of penultimate 010 This animal was about the size of the raccoon, and probably had the habits of tbo tapirs. BATHMODON SIMUB, sp. nov. Represented by the remains of a great number of individuals, including all parts of the skeleton, dentition, & c, but especially by one of the most complete, of these, which possesses, among other portions, the premaxillary bones. These indicate a species very distinct from the li. radians, Cope, and one approaching the Metahphodon armatus iu the structure of the molar teeth. The canine teeth have cylindric roots and trihedral crowns, the section of the latter forming a nearly equilateral spherical triangle. The crown of the inferior canines arc shorter, and have one concave side. The superior molars support two crests, which are nearly parallel on the single and last tooth of this type. The posterior crest is composed of two portions, the posterior conic and the anterior flatter, and which becomes the external posterior crescent on the penultimate molar. The anterior cingular crest is very well developed on the last lower molar. The premaxillary bone is short and stont, and descends steeply from an elevated front, presenting its three teeth downward. The canine follows closely from an elevated rib on the side of the face. Behind it is a considerable diastema. The humerus is a very stout bone, and the femur is rather slight in comparison with it. Measurements. Length of bases of last three molars 083 Length of basis of last molar 026 Width of basis of last molar 035 |
