w. 



■U j ; ! , 





(ill 





046 



MONOGRAPHS OF NORTH AMERICAN RODENTIA. 



Genus P8EUDOTOMUS Cope. 



PttHdotomtu CoPK, Proo. Amer. Pbil. Soc. IH7-A4ri7; IT. S. Geol. Surv. Terr. 6th Aon. Rep. (for 1873), 

 1873, 610. 



Skull depressed ; zygomata considerably expanded ; muzzle brond, but little ele- 

 vated, witb tbe nasal meatus between the alveoli of the upper incisors ; frontals very 

 sbort, tbe superciliary margin and orbits small, and without postorbital processes; 

 temporal fossa) large, converging posteriorly, and greatly contracting tbe braiu case 

 behind tbe orbita; infraorbital .foramen rather small, circular, and placed low down 

 near tbe alveolar border ; upper iucisors relatively small, in form much as in Arctomyn, 

 but more widely separated ; molars probably J. 



This genus was tirst referred by its describer to the order Edentata, but later was 

 considered as "allied to, if not actually a member of, the Sciuridw". The breadth and 

 depression of the skull are said to remind one of ArctomyH, from which, however, it 

 differs in tbe contraction of the skull between the orbits, in this respect more resembling 

 Fiber. It seems also in this and in other respects to strongly recall I»ckyromy». Tbe 

 lateral separation of tbe iucisors, both superior and inferior, is referred to as a marked 

 peculiarity. Known from a single imperfect skull and one or two mandibular fragments 

 from the Bod Lands of Cottonwood Creek. -;. 



PSEUDOTOMUS HUNS Cope. 



PKudoUmut hiant Cope, Proc. Amer. Pliil. Soc. 1W72, 407 ; U. 8. Geol. Surv. Terr. 6th Ann. Rep. (for 187i), 

 187;), 611. 



The single imperfect skull trom which the present species is known is said to iiidi- 

 isa\» an animal of "about the size of an Agouti". From tbe Fort Bridger Eocene. 



MYOMORPHA. 



MURID^. 

 Genus EUMYS Leidy. 



E»my» Lkidy, Proc. Acad. Nut. Sci. Phila. I8.'i6, 90. 



EUMYS ELEGANS Leidy. 



A'umyf eUgatu Leidy, Proc. Acad. Nat. Sci. Pliila. 1806, 9U; 1857, 89; Journ. Aowl. Nat. Sol. 8d nr. vli, 

 1869, Mi, 407, pi. xxvi, figs. 12, la.— Cope, Rep. U. S. Geol. and Geog. Surv, Terr, for 1873, 

 1874, 474. 



The genus and species were described by Or. Leidy from a specimen discovered by 

 Dr. Haydeu in tbe Bad Lauds of Bear Creek, "con»iisting of a portion of the left side 

 of a lower jaw". This jaw-fragment is said to indicate "an animal approaching in 

 size tlie Brown Riit (Mu« deeutnanvs)'', and to agree in form and constitution with tho 

 corresponding portion of the jaw of that animal. 



EUMYS LOXODON Cope. 



Heiperomyt lozodon CoPR, Proc. Acad. Nat. Sci. Phils. 1874, 150. 



Eumj/i loxodoH Copu, Ann. Rep. Cbf. Eagiuoers, 1874, 605; ill. App. LL, 1. 



Based ou un entire mandibular ramus, with all the teeth preserved, from the Hanta 

 F6 marls. Similar to tbe E. elegans of Leidy. 



NEOTOMA MAOISTER Baird. See nnteA, p. 29 



