52 PATAGONIAN EXPEDITIONS: PALEONTOLOGY. 



Measurements. 



Upper molar series, length . . .038 M-^, width . . . . . .019 



Mi, length {i, e., ant. -post, diam.) . .013 M-^, length 013 



" width (/. f., transverse diameter) .018 " width 020 



M^, length 014 



SPECIES INCERT^ SEDIS. 



The two following species, which have been referred to Licaphrium, are 

 not sufficiently well known to make clear their generic reference. 



LiCAPHRiUM DEBiLE Amcghino. 



Licaphrhim debile Amegh.; Enum. Synopt. des Mamm. Foss. de Patagonie, 

 1894, p. 42. 



LiCAPHRiUM TENUE Ameghino. 



Licaphrhim tenuce Amegh.; Ibid., p. 43. 



This is the smallest known Santa Cruz representative of the family, but, 

 further than to say that it is not a species of Thoathermm, it is not possi- 

 ble to go with the existing material. 



LICAPHROPS Ameghino. 



Licaphrops Amegh. ; An. del Mus. Nac. de Buenos Aires, Ser. 3, T. 

 Ill, p. 448. 

 I have seen no example of this genus, which is characterized by the 

 great development of the antero-internal cusp (protocone) of the upper 

 molars and the great reduction of the postero-internal cusp (hypocone), 

 giving the crown a somewhat triangular shape. 



Licaphrops coalescens Ameghino. 



Licaphrops coalescens Ameghino ; Loc. cit., p. 455. 



This, the only known species from the Santa Cruz beds, is represented 

 by a single upper molar, which measures 15 mm. in antero-posterior by 

 13 mm. in transverse diameter. 



PROTEROTHERIUM Ameghino. 



(Plates VII, Figs. 8-1 1 ; VIII-X ; XI, Figs, i-i i ; XII, Figs, i, 2 ; XIII, Fig. 8.) 



Proterotherittm Amegh.; Bol. de la Acad. Nac. de Cienc. de Cordoba, T. 

 V, 1883, p. 291. 



