ART. 7 A FOSSIL RHINOCEROS FROM MONTANA — WOOD 6 



Loup Fork. I have always considered them as Wliite River." The 

 discovery of this skull is an approximate confirmation of Douglass's 

 opinion. 



That the beds on the west side of the Madison River, south of 

 Three Forks, may not be of John Day age, throughout, is suggested by 

 a right M^ referable to {?)Aphelops ceratorhinus Douglass in Mr. 

 Kinsey's collection. (Douglass collected the type specimen in the 

 lower Madison Valley, about 5 miles south of Logan.) Mr. Kinsey 

 found this tooth, in loose dirt, on the opposite (southern) side of the 

 westwardly jutting point on which he found the Diceratherium skull. 



Table 1. — Measurements of two specimens of Diceratherium armatum Marsh 



Measurement 



Pi-M3. 



P2-M3. 



p2-4 



M>-' 



Pi, A-P 



pi, Tr.. 



P2, A-P 



pa, Tr. 



P», A-P 



P3,Tr 



p«,'a-p - 



P<, Tr... 



M', A-P 



Ml, Tr 



M2, A-P 



M2, Tr 



M\ A-P 



M3, Tr 



A-P, rear of nasal rugosity to anterior tip of nasal. 



U.S.N.M. No. 11682 



Y.P.M. No. 10003 

 (holotype) 



Right 



Mm 

 250. 

 225. 

 128. 

 102. 

 126. 



26. 

 '•22. 



31. 

 41. 



35. 



51. 



35. 



54. 



40. 



54. 



43. 



57. 



44. 



52. 

 124. 



Left 



Mm 



128.7 

 104.6 



26.5 

 '23.1 

 31.5 

 '42.7 

 36.1 

 50.5 

 36.5 

 53.5 



116.0 



After 



Tro.Tell, 



1921 



Mm 

 254 



129 



144 

 29 

 27 

 33 

 39 

 39 

 47 

 40 

 51 

 52 

 53 

 55 

 57 

 47 

 50 



After 



Peterson, 



1920 



Mm 



248 



" Measured across metaloph. 



About 5 years ago, a rhinoceros lower jaw with left Pg-Ma, which also 

 is probably referable to {?)Aphelops ceratorhinus, was collected about 

 a mile south of this locality, the exact location and condition of occur- 

 rence being unknown. It was this discovery that led to Mr. Kinsey's 

 collecting in this region. If the two specimens were in place thej^ 

 indicate the presence of otherwise unrecognized Madison Valley beds 

 on the west side of the Madison River. The matrix adhering to the 

 outside of this skull is a coarse sandstone, indicating deposition in 

 a stream channel ; some of the matrix inside the fragment of the brain 

 case is much finer. This bed, then, is uppermost Oligocene, or. 



