H. lustrata Amegh., 1901, Bol. Acad. Cienc. Cordoba, t. 16, p. 405.

This species is smaller than the preceding, and is based on an upper molar 1 and a last lower molar. The measurements are as follows:

Upper molar 1,length25 mm.,width25 mm.
Lower molar 3,length 25 mm.,width 12 mm.

Fig. 91. H, inaequilatera, upper molars 3 and 4—
natural size, after Ameghino.

H. inaequilatera Amegh. loc. cit. above.

This species is larger than the preceding with the internal cingulum more developed. Upper molar 2 measures 30 mm. long by 29 mm. wide.

H. circumdata Amegh., loc. cit. above.

This is a still larger type, with the internal cingulum enormously developed. Upper molar 1 measures 42 mm. long by 36 mm. wide.