I02 KANSAS UNIVERSITY QUARTERLY. 



TETRACAULODON SHEPARDII, COPE. 



?? Tetracaulodon mastodon toideum, Godman; Trans. Am, Phil. Society, N. S., 

 Vol. 3. p. 478, (1830) 



? Mastodon shepardii; Leidy, Proc. Ac. Nat. Sc, Phila., 1870, p. 98. 



? Mastodon shepardii; Leidy, Proc. Ac. Nat. Sc, Phila., 1872, p. 142. 



? Mastodon obscurus; Leidy, Rept. U. S. G. and G. Survey of Terr., Vol. i, p. 

 330, Plate 21, (1873). 



Mastodon shepardii; Cope, Am. Naturalist, 1884, p. 525. 



Dibelodon shepardii; Cope, Proc. Am. Phil Soc, Vol. 22, p. 5, (1884). 



Tetrabelodon shepardii; Cope, Preliminary Report on the Vertebrate Paleon- 

 tology of the Llano Estacado, p. 57, Plate 15. 



It requires no extended study to discover that in the taxonomy 

 of mastodons a confusion little short of hopeless reigns supreme. 

 Much of this is due to the usual fragmentary state of specimens; 

 but the fact that species after species has been erected on the evi- 

 dence of single, often fragmentary, teeth, does not help matters. 

 Considering the peculiarities of elephantine dentition, and the 

 seemingly very great tendency toward variation and intergradation 

 such species must in most cases be considered worthless, except 

 where corroborated by further material. * 



If it shall ever be possible to make a study of American mastodons 

 as a whole, with ample material, a considerable reduction in the 

 number of species may be looked for. 



In 1830 Godman described the genus Tetracaulodon, with char- 

 acters that seem perfectly valid. The genus was recognized for 

 ten or fifteen years and then resubmerged in Mastodon. The type 

 species may be the same as the one here under discussion, but at 

 present I am unable to verify the supposition. 



In 1870 Leidy based his M. shepardii on a single specimen of 

 tusk, and that a fragment only six inches long. It can hardly be 

 considered a valid name. Later on he merged the species into M. 

 obscurus., a species based on material almost equally insufficient, a 

 single tooth. 



In 1884 Cope revived the species sJiepardi without, however, 

 any further characterization. Later in the same year he made it 

 the type of his genus Dibelodon. Lastly in 1893, he referred to 

 this species {shepardii, he now spells it), a nearly complete lower 

 jaw from Texas, and as this showed the presence of lower tusks he 

 transferred the species to his genus Tetrabelodon. Here he also 

 gave for the first time, an adequate description, and the species, it 

 seems to me, should date from here. The genus name, however, 

 cannot stand. The four-tusked genus called by Cope, Tetrabelodon, 

 is certainly well characterized, but its characters were well stated 



