Vol. 5] 



Kellogg. — Rode n t Fa u na. 



429 



APLODONTIA ALEXANDRAE Furlong. 



This is a small species described by Mr. E. L. Furlong in the 

 University of California Publications in Geology, vol. 5, p. 398. 

 The most important specific character is the presence of a prom- 

 inent style on the inner posterior portion of the lower teeth, 

 instead of in the median region. It occurs in the Tertiary beds 

 at Virgin Valley, and also at Thousand Creek. 



MYLAGAULUS MONODON Cope. 

 Figs 9a, 9b, 10, a and b. 



No. 11878, left P 4 from locality no. 1098, Thousand Creek; 

 and nos. 11572, a left P 4 , and 11662, a right P 4 , from locality 

 no. 1065 in Virgin Valley, Humboldt County, Nevada. 



No. 11878, although an unworn tooth, exhibits a pattern that 

 with age would evidently resemble that shown in the figure of 

 Mylagaulus monodon, no. 9043, as presented by Matthew in the 

 Memoirs of the American Museum of Natural History. 3 



Nos. 11572 and 11662 represent teeth in different stages of 

 wear, the former being worn and the latter unworn, so that they 

 do not agree exactly in the enamel pattern. They are referred to 

 Mylagaulus monodon Cope, although the number and arrange- 

 ment of the lakes do not show an exact resemblance to any figures 

 of that species shown. 



Measurements. 



No. 11878 No. 11572 No. 11C62 



P 4 , anteroposterior diameter 7.5 mm. 



P J , transverse diameter (3.0 



P 4 , anteroposterior diameter 8.8 mm. 8.6 mm. 



P 4 , transverse diameter 5.2 5.0 



MYLAGAULUS PRISTINUS Douglass. 

 Figs. 11, a and b; 12, a and b. 

 Nos. 11843, 11684, 11540, left P 4 , from locality no. 1090. No. 

 12579, a left P 4 ; and no. 12580, a right P 4 ; both from locality 

 no. 1095, Virgin Valley, Humboldt County, Nevada. 



■'■ Mem. Am. Mus. Nat. Hist., vol. 1, p. 379, fig. 5. 



