Peterson: Material Discovered in Uinta Basin. 61 



Measurements. 



Length of cheek-dentition i8 mm. 



Vertical diameter of ramus at Mv 13 mm. 



9. Paramys medius sp. nov. (Plate XXXIV, Figs. 15-22). 



Type: Fragment of maxillary with three teeth, and fragment of 

 lower jaw, C. M. No. 3048. 



Horizon: Uinta Eocene Horizon C. 



Locality: Six miles east of My ton, Utah. 



' Characters of Type: Of same size as Paramys delicatus, but with 

 broader summits of the unzvorn crowns of the molars and with the inner 

 and outer faces more vertical. The hypocone is also somewhat more 

 set off from the protocone, and the styles of the outer cusps and the hypocone 

 are more prominent than in the Bridger species. The lorhikled appear- 

 ance of the enamel suggests that this species is referable to Taramys ' 

 (Gidley). 



The total length of the three upper teeth is 13.4 mm. 



A few fragments of vertebrae and limb bones together with portions 

 of hind feet representing three individuals C. M. Nos. 3374, 3374a, 

 and 3376, found by Mr. Earl Douglass at the base of horizon C near 

 Kennedy's Hole, were referred by myself provisionally to Paramys 

 uintensis. Mr. Gidley who has recently very kindly compared this 

 material with other specimens in the U. S. National Museum, advises 

 me, that, if these remains are to be referred to any described species, 

 he would place them with P. medius described above rather than with 

 P. uintensis "since the former is about the size of P. delicatus, and this 

 foot agrees also in size with that of P. delicatus, being only slightly 

 more robust." The specimens are apparently somewhat large to be 

 regarded as P. sciuroides, and too small and apparently of different 

 proportions from P. robustus Marsh or P. (Ischyrotomus) peter soni 

 Matthew.^'' The hind foot as a whole appears to be relatively broader 

 and shorter, while the distal end of the metatarsals is more suddenly 

 expanded and the articulations are more rounded than in the foot of 

 P. robustus figured by Dr. Matthew.^^ 



The calcaneum and astragalus appear to be very similar to these 

 bones in P. robustus. Among recent forms they most nearly suggest 



^'' Bull. Amer. Mus. Nat. Hist., Vol. XXVII, 1910, p. 49. 



'' In a letter of May 22, 1916, Mr. Gidley says in this connection: "While this 

 foot resembles in a general way those of P. robustus and P. delicatus, the differences 

 are sufficiently great to make its reference to this genus very doubtful." 



