43O PATAGONIAN EXPEDITIONS: PALAEONTOLOGY. 



Amegh, Coll. 

 My, antero-posterior diameter ........ .003 



M T , " " 002 



Depth of mandible below M^ . . . . . . . . .0075 



" " " M T 008 



PAL/EOTHENTES INTERMEDIUS Ameghino. 



(Plates LXIII, Figs. 3, 7 ; LXIV, Figs, I, ia.) 



Palceothentes intermedius Amegh. ; Enum. Sist. Especies Mamif. Fos. Pata- 

 gonia Austral, p. 6, 1887. 

 Epanorthus intermedius Amegh.; Contrib. al Conocimiento Mamif. Fos. 



Rep. Argentina, p. 274, PI. I, Figs. 15-15^, 1889. 

 Metaepanorthus intermedius Amegh.; fenum. Syn., etc., p. 92, 1894; Bol. 



Acad. Cordoba, p. 348, 1894. 



An incomplete skull (No. 15,225) collected by Mr. Peterson from the 

 Lower Santa Cruz beds five miles south of Coy Inlet, and two maxillary 

 fragments (No. 15,952; American Museum, No. 9550), from Killik Aike 

 and Santa Cruz respectively, apparently belong to this species, agreeing 

 closely with the measurement given by Ameghino (1894, p. 92) for the 

 premolar-molar series. The important features of the skull and teeth have 

 already been mentioned in characterizing the genus. 



So far as can be judged from the small amount of material available, 

 the size of mature individuals is fairly constant. The upper premolars 

 are all double-rooted, without intervening diastemata. The anterior pre- 

 molar is in contact with the canine. An exceedingly small anterior ac- 

 cessory basal tubercle is present on the upper sectorial in unworn teeth. 

 The species is considerably larger than P. lepidus, occupying in point of 

 size a position intermediate between that species and P. aratce. 



MEASUREMENTS. 



No. 15,225. No. 15,952. No. 9550. 

 Length of upper premolar-molar series meas- 

 ured as chord of arc . . . .015 .015 

 Length of space occupied by upper premolars -0075 .0074 

 " " " " " " molars . .0085 .0085 

 Anterior premolar, antero-posterior diameter .0018 

 " " transverse " . .0008 

 Median " antero-posterior " . .002 .002 

 " " transverse " .001 .001 



