854 THE JOHN DAY FAUNA. 



Paciculus insolitus Cope. 



Locis citatis. 

 Plate LXVI; figs. 31,32. 



Size small. Molars regularly and rapidly diminishing in size poste- 

 riorly. Inner enamel loop turned forwards; the external straight and trans- 

 verse, excepting in the first molar, where the anterior column of the tooth 

 is extended forwards, and the anterior loop is turned backwards. No fos- 

 settes. The first molar is longer than wide, and is contracted forwards ; the 

 second and third are subquadrate in form, with the inner angles rounded. 

 The palate is wide, considerably exceeding the long diameter of the first 



molar. 



Measurements. 



u. 



Length of superior molar series 0060 



( anteroposterior 0021 



Diameters of first molar I j^^^^^^^g^ ^,^^3 



Length of third molar 0010 



Width of palate at first molar 0040 



The Paciculus insolitus is about the size of the Chipmunk, Tamias 



striatus. 



Paciculus lockingtonianus Cope. 



Eumys lockingtonianus Cope, Bulletin U. S. Geological Survey, Terrs., VI, 1881, p. 176. 



Plate LXIV ; fig. 10. 



This rodent is represented by a nearly perfect skull, which is without 

 jower jaw. Its specific characters separate it widely from the Eumys elegans 

 Leidy and Hesperoniys nematodon Cope. It is considerably larger than either, 

 and the temporal ridges are very obsolete and do not unite posterior to the 

 orbits, as in E. elegans, resembling in this respect the H. nematodon. The 

 parietal region is wide and flat above. The interorbital region is only mod- 

 erately contracted. The muzzle is rather short as compared with the total 

 length of the skull. The interorbital region is gently convex above, and the 

 top of the muzzle is flat. The zygoma is quite slender, and the otic bullae 

 are large and prominent. The notch of the palate extends as far forwards 

 as the posterior part of the last superior molar. The infraorbital foramen 

 is very large and round. 



