. Bulletin - United States National Museum. Science. 48 BULLETIN 57, UNITED STATES NATIONAL MUSEUM. Cli(()'((cfe)'s.âDental fonimla : - 2 3. 1. -2 3 4 5 - 1 2 -. 1. -2 3 4 5 f> .2-2 1-1 '' 2-2' ^ i^^' 3-3 1-1 3:::3' ^^ %^- Teeth Avithont special modifications. Upper incisors in contact with each other, but separated from canine by wide diastema, nearly terete, their crowns slightly flattened antero-posteriorly, the inner tooth of each pair slihtly long:er than the outer. Lower incisors somewhat flattened laterally, the outer of each pair slightly the larger; cutting edge l)lunt, nearl
. Bulletin - United States National Museum. Science. 48 BULLETIN 57, UNITED STATES NATIONAL MUSEUM. Cli(()'((cfe)'s.âDental fonimla : - 2 3. 1. -2 3 4 5 - 1 2 -. 1. -2 3 4 5 f> .2-2 1-1 '' 2-2' ^ i^^' 3-3 1-1 3:::3' ^^ %^- Teeth Avithont special modifications. Upper incisors in contact with each other, but separated from canine by wide diastema, nearly terete, their crowns slightly flattened antero-posteriorly, the inner tooth of each pair slihtly long:er than the outer. Lower incisors somewhat flattened laterally, the outer of each pair slightly the larger; cutting edge l)lunt, nearly flat, though divided by a shallow notch into two in- conspicuous lobes. Canines both above and below with a secondary cusp on imier side formed by a slight prolonga- tion of the cingulum and some- what variable in its develop- ment in different species. An- terior upper premolar perma- nent, but scarcely larger than incisor in cross section and so short as barely to penetrate the gum. Its crown is nearly flat, though with a faintly in- dicated antero-external cusp. The corresponding lower tooth is considerably larger, its disk- shaped crown somewhat con- cave except for the minute antero - external cusp. The three suceeding cheek teeth almost exactly resemble each other above and below; j»u 'â 'â and pin ,. are higher and shorter than the others, and the inner ridge tends to form a blunt cusp opi^osite base of main cusp; pm\ w% p?n^, and m^ have the longitudinal furrow well de- veloped and bounded on the inner side by a distinct, though low, ridge, and on the outer side by a much higher ridg'e, which rises anteriorly into a blunt cusp. Their crowns are noticeably longer than broad. The sec- ,ond lower molar closely resembles the anterior lower premolar, except that it lacks the small antero-internal cusp. The skull (figs. 5, G) very primitiA'e in form, the ventral profile nearly straight, the dorsal pro- file showing no special i^eculiarities. Floor of brain case scarce
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Keywords: ., bookauthorun, bookcentury1800, bookdecade1870, booksubjectscience
