ART. 1. PRIMATES OF THE FORT UNION GIDLEY. 3 



Family TARSIIDAE 



This family, as defined by Matthew,^ seems to be represented in 

 the Fort Union by six new species representing four genera, three 

 of which are new. These suggest more or less close relationships to 

 the known Eocene members of the group, but do not fall within the 

 definition of any of the described genera of these later beds. 



PAROMOMYS, new genus. 



Genotype. — Paromomys maturus, new species. 



2 1 "^ "^ 



Diagnosis. — Dental formula: I — '— , c -, p -, m ~: Species of 



1 or 2 1 3 3 



small size with anterior tooth modifications in general as in the 



Omomids; that is, with unreduced canine and enlarged median incisor; 



but with molar developments suggesting Notharctus or Pelycodus in 



that they have a lengthened and broadened heel in m.^, and the 



trigonid is composed principally of the subequal protoconid and 



metaconid which tend to unite at the summits to form cross lophs; 



trigonids relatively high and distinctly directed forward. 



Other principal features are total absence of internal cingula on 



the upper molars, the complete continuation of the hypocone ridge 



to the summit of the protocone, and the relatively greater height of 



the trigonids of the lower molars. These last two characters seem to 



be directly associated with and to precede the stage in which a true 



hypocone is developed. In all forms of this group the development 



of a true hypocene is accompanied by a corresponding depression of 



the trigonid. 



PAROMOMYS MATURUS, new species. 



Figure 1, and Plate 1, figure 3; also Figure 2, and Plate 2, figures 2 and 3. 



Type. — Portion of a right lower jaw carrying four teeth, p^ to va^ 

 and alveoh for the anterior teeth. (Cat. No. 9473, U.S.N.M. Coll.) 



Locality.— ''G'ldlQj Quarry, "■^ sec. 23, R. 15 E., T. 5 N., Sweetgrass 

 County, Montana. 



Horizon. — Near top of Fort Union " No. 2," of Silberling (Paleo- 

 cene Tertiary as published by Calvert and Stone) . This level or stra- 

 tum is about 1,300 feet above the base of the beds, which here lie 

 apparently conformably on the Lance formation, and is more than 

 4,000 feet below the top of the Fort Union in this section. 



The species is represented in the collection by portions of upper 

 and lower jaws and teeth of more than 40 individuals, all from the 

 " Gidley Quarry." 



'Bull. Amer. Mus. Nat. Hist., vol. 34, 1915, p. 445. 



*This name was given by Mr. Silberling in his field notes to designate this locality, and is here used 

 or convenience. 



