1921] FricJc: Faunas of Bautista Creek and San Timoteo CaFion 409 



Comparison.- — In the three crests of the intermediate, the four crests 

 of the last molars, and the simple pattern of the tubercles the Eden 

 specimens differ markedly from the complex four-crested intermediate, 

 and six-crested last molars of Tetralophodon mirificus Leidy of the 

 Niobara and T. campester Cope of the Blanco. In the presence of but 

 three transverse crests in the intermediate teeth, the new material 

 comes within Matthew's recent definition of the genus Trilopliodon^^ 

 as distinguished from Tetralophodon. 



The Eden teeth lack the elaborated complex pattern and tuber- 

 eulated eingula of Trilophodon floridanus Leidy. The last molar of the 

 new type specimen somewhat suggests the last lower molar from the 

 San Joaquin Valley of California described by Leidy and tentatively 

 referred by him to his type Tetrabelodon shepardi.'"^ The resemblance 

 is marked in the four well separated cross crests, in the very rudi- 

 mentary heel of the last molar, and in the trefoil pattern exhibited 

 by the outer halves of the transverse crests of the worn teeth and 

 the small oval pattern of the inner halves.**" Moreover, the tusks of 

 the present specimen show the enamelled band noted by Leidy in his 

 original description, which was based on the six inch section of tusk 

 from Dry Creek, Stanislaus County."^ 



Further material from the San Joaquin vicinity and from Eden 

 may possibly prove the Eden specimens, the last lower molar from 

 Contra Costa County, the referred section of the small tusk (of Leidy 's 

 original description), and the portion of a second and somewhat broken 

 molar from Stanislaus County, California, to represent one and the 

 same species. For convenience in future reference, the Eden form is' 

 here referred to T. shepardi as a new subspecies under the name of 

 the locality, Trilophodon shepardi edensis. 



58 Matthew, W. D. Tertiary Mammalia Cope and Matthew, explanation plate 

 120. 1915. 



59 Leidy, Jos. Proc. Acad. Nat. Sci. Phil., pp. 98 and 99. Sept., 1870, and 

 U. S. G. S. of Terrs., vol. V, p. 232. 1873. 



80 A four-crested last lower molar with rudimentary heel, from Oregon (Univ. 

 Calif. Publ., Bull. Dept. Geol., vol. 10, p. 134, fig. 3) somewhat suggests the 

 present specimens, as do also the associated four lobed last molar and three lobed 

 intermediate molar from Thousand Creek, Nevada (illustrated I.e. Merriam, 

 vol. 6, pi. 33). 



81 A similar partial enamel covering has been noted on the fragments of two 

 large tusks from the upper Miocene of Nevada (I.e. Merriam, vol. 9, p. 189). 



Transmitted November S8, 1917. 



