28 



V Measurements. 



M. 



Length of series of inferior molars 0. 370 



Long diameter of canine alveolus (28.5 lines) 060 



Length of true molar series 140 



Length of crown of fourth premolar 053 



Height of crown of fourth premolar, (worn) 022 



Width symphysis between canines 090 



Length of chin process, (3.5 inches) 090 



Width anteroposteriorly 080 



Length of interval to tlae second tuberosity 150 



Length of basis of the second tuberosity 075 



The only species which it is necessary to compare with the U. ramosum, 

 in respect to size, is the E. imperator Leidy, {U. superbum Leidy, an 

 older but less appropriate name,) kuown from a few teeth (none molars) 

 from California and Oregon. The long diameter of the canine is to that 

 of U. ramosum as 5 J m 7^. 



Symboeodon TEiaoNOCERAS Cope. Svnopsis of ISTew Vertebrata, Colo- 

 rado, 1873, p. 13. 



This species has recently been described by Prof. O. C. Marsh under 

 the name of Brontotherium ingens, and a cranium figured, in the Ameri- 

 can Journal of Science and Art, 1874, p. 85. The advance copies bear 

 date December 30, and are therefore subsequent to the issue of the 

 "Synopsis" above cited, which took place on October 16. Several 

 crania in my possession agree with the one figured by Professor Marsh. 

 A large proportion of the characters mentioned in his paper as charac- 

 teristic of the species aud genus will be found in the Synopsis, p. 14, 

 and in the Paleoutological Bulletin, No. 15, pp. 3-5 ; aud the ascription 

 of a proboscis to the genus in the "Independent" (New York) for Oc- 

 tober 30, 1873. Professor Marsh states that the genus ISymborodon 

 Cope is not distinct from Brontotherium Marsh. The latter was de- 

 scribed by him as possessing four inferior incisors ; in Symborodon there 

 are no inferior incisors whatever. This I have verified on perhaps a 

 dozen mandibles of several species. 1 have not identified any as cer- 

 tainly belonging to this one; so that it it possesses incisor teeth, as 

 stated by Protessor Marsh, it shoukl be called Brontotherium trigo- 

 noceras. 



Published January 21, 1874. 



