1916] 



Merriam: Fauna of Cedar Mountain Region 



179 



The writer considered the possibility that no. 19798 represents 

 a milk premolar of a form like the Recent Aplodontia, and was 

 fortunate in finding in the California Museum of Vertebrate Zoology 

 a specimen with Dpm 4 well preserved. Dpm 4 of the Recent Aplodontia 

 resembles specimen 19798 in the reaching down of the enamel valleys 

 almost to the bottom of the relatively short crown, but the number 

 of the enamel lakes does not correspond to that in no. 19798, and 

 the roots of Dpm 4 of the Recent form are much more divergent than 

 in the fossil specimen. Divergence of the roots seems to be a necessary 

 character in the Dpm 4 in order to permit P 4 to come down between 

 the roots. 



Though specimen 19798 is evidently nearest to Aplodontia, it shows 

 an interesting resemblance to Meniscomys. In Meniscomys there are 

 four valleys which are more pronounced than any other features of 

 the occlusal surface, and a slight elongation of the crown with deepen- 

 ing of the valleys might produce in wear a section quite similar to 

 that in specimen 19798. 



The less rounded anterior side of the tooth in no. 19798 is more 

 as in Meniscomys, as are the short crown and the non-divergent roots. 



The exact relationships of this form are uncertain, more than that 

 it quite certainly belongs with the Aplodontidae. It apparently lies 

 between Aplodontia and Meniscomys, but is much nearer Aplodontia. 

 Unless the specimen should be found to represent Dpm 4 of an unknown 

 species related to Aplodontia alexandrae, it probably pertains to a 

 genus intermediate between Meniscomys and Aplodontia. 



Measurements 



Aplodontia Aplodontia 

 No. 19798 rufa alexandrae 



P 4 , greatest anteroposterior diameter ap 4.2 mm. 5 3.5 



P 4 , greatest transverse diameter 3.9 5 4. 



P 4 , height of portion of crown remaining .... 2.8 

 ap, approximate. 



LEPIJS, near VETUS Kellogg 



Two teeth from the collection at Stewart Valley, locality 2027, 

 represent a leporid form which is near Lepus vetus, found in the Virgin 

 Valley Miocene and Thousand Creek Pliocene of Nevada, but is prob- 

 ably specifically different from that form. 



The teeth examined are slightly curved. The convex inner face 

 shows a deep fold, the borders of which exhibit numerous secondary 



