23 



MEASUREMENTS. 



Longtii of premolar 3 0115 



Width of premolar :i 012 



liength of premolar 4 010 



\A' idth of premolar 4 0125 



Length of molar series, about 044 



Length of molar 1 014 



Width of molar 1 ^ 016 



Length of molar 2 016 



"Width of molar 2 017 



Length of molar ;'., al)()ut 016 



Width of molar 3 016 



From the Loiip Fork beds of the lower Madison. 



PALAEOMERYX MADISONIUS. N. SP. 



Besides the teeth and jaw deseribed under F. americanus I have 

 an upper third premolar, and part of a mandilde. found in different 

 loealities. These belong to a larger species. This is evidently a 

 younger animal than the smaller one just described. The teeth are 

 higher, being less worn. The enamel is ronghened as in that species. 

 The Palaeomeryx folds are plainly seen on the three molars, which 

 are the only teeth preserved. The median internal pillars are smaller 

 proportionally. There is a small one between the second and third 

 crests of molar 3. This ramus lacks the long depression near the 

 lower border, but there is a broad, , shallow concavity on the inner side. 



MEASUREMENTS. 



Molar 1. Molar 2. Molar 3. 



M. M. M. 



Length, about 013 about .015 about .023 



Breadth 0095 .010 .0103 



Height 0085 .010 .0115 



The upper third premolar difft'rs from the corresponding tooth 

 of P. americanus in its greater size and the greater wear has divided 

 the long enamel lake into two smaller ones, and the small lake on the 

 posterior side is narrow, longer, and more crescentic. The association 

 of this tooth with the above described jaw fragment is simple pre- 

 sumption. 



COSORYX AGILIS. N. SP. 



Plate IV, PMgure 1. 



In the bluffs which lie on the eastern side of the lower Madison 

 valley, I found several fragments of small animals related to the an- 

 t.'lopes. Two or three jaw fragments are like Blastomenjx fjemmifer 



