The Deseado Formation of Patagonia

by Frederic Brewster Loomis

T. scalaris Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 483, is based on lower pm. 2 to m. 2, a somewhat smaller species than the preceding, the series as given measuring 53 mm.

Fig. 88. T. scalaris, premolar 2 to molar 2—
natural size.

T. angustus Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 484.

This species is described without a figure, as smaller than T. scalaris, pm. 2 to m. 2 being 59 mm. The mandible is also slenderer.

T. biconus Amegh., 1897, Bol. Inst. Geog. Argen., t. 18. p. 484.

This species is based on two lower premolars, said to be the same size as T. angustus, but with the pillar larger.

Pleurocoelodon Ameghino

Pleurocoelodon, Amegh., 1895, Bol. Inst. Geog. Argen., t. 15, p. 645.
Pleurocoelodon, Amegh., 1897, Bol. Inst. Geog. Argen., t. 18, p. 484.

This genus is distinguished by the absence of the style on the anterior external margin of the upper molars, instead of which the external face is excavated medianly. Two species are described, based on isolated upper teeth.