C. scalpridens Amegh., 1895, Bol. Inst. Geog. Argen., t. 15, p. 630.
C. scalpridens Amegh., 1897, Bol. Inst., Geog. Argen., t. 18, p. 459.
C. cancellatus Amegh., 1901, Bol. Acad. Nac. Cienc. Cordoba, t. 16, p. 374.
Fig. 82. Sections of second lower molar;
A, top; B, 4 mm. down; C, 10 mm. down;
D, 18 mm. down—natural size.
Of this species we found two specimens, one containing the three lower molars, the other the second lower molar only. In establishing C. cancellatus, Ameghino says it is of the same size as C. scalpridens, but distinguished by the basin in the upper molars being narrower, the internal fold not being bifurcated, and by the absence of islets of enamel. All these features seem to me to be the results of wear.
Fig. 83. Molars 1 to 3—natural size.
While the pattern of the upper molars is the same as in Proadinotherium, these teeth are about as wide as they are long. The lower molars, however, are more compressed, with the anterior crescent occupying about a third of the tooth, and having in the early stages a deep pit, which disappears when the tooth is worn down. In the middle of the basin of the posterior crescent is a large pillar, and between this and the median horn of the crescent is a tiny septum, which early unites with the pillar, leaving a tiny pit (3) which soon disappears entirely. In fact, in an old tooth, the second and fourth bays, having become pits, may even be lost also.
| Measurements | ||
|---|---|---|
| Upper dentition, | molar 1, length | 19 mm. @ Ameghino. |
| Upper dentition, | molar 1, width | 12 mm. @ Ameghino. |
| Upper dentition, | m. 1 to m. 3, length | 52 mm. @ Ameghino. |
| Lower dentition, | premolar 2, length | 13 mm. @ Ameghino. |
| Lower dentition, | premolar 3, length | 13 mm. @ Ameghino. |
| Lower dentition, | premolar 4, length | 17 mm. @ Ameghino. |
| Lower dentition, | molar 1, length 18 mm., width | 7 mm. |
| Lower dentition, | molar 2, length 19 mm., width | 7 mm. |
| Lower dentition, | molar 3, length 20 mm., width | 7 mm. |
Interhippus Ameghino
Interhippus Amegh., 1904, Anal. Mus. Nac. Buenos Aires, ser. 3, t. 3, p. 183.
Interhippus Amegh., 1904, Anal. Soc. Cienc. Argen., t. 56, p. 34 of reprint.