WAGNER: TETRACAULODON (tETRAKELODON) SHEPARDII. IO3 



by Godman more than a half of a century earlier, and his name is 

 entitled to precedence. That Dibclodoii is a valid genus I very 

 much doubt. I am very much inclined to believe that the forms 

 referred to it are only females of Tetracaulodon. 



How many species of Tetracaulodon we have is yet to be decided. 

 T. ciihypodon, Cope is probably synonymous with shcpardii, as may 

 be T. product us. Mastodon floridanus, Leidy*, agrees in practically 

 all points with T. slicpardii. I hesitate in referring it to that species 

 only on account of a more pronounced tubercular structure of the 

 teeth in M. floridanus (which difference may be less than the plates 

 seem to indicate), and on account of the fact that the specimens of 

 last lower molars described by Leidy are fully 25 per cent larger 

 than in any recorded specimen of T. shcpardii. 



To Prof. Williston I am much indebted for constant aid in this 

 as in other investigations, as well as for the use of specimens and 

 literature. To Prof. Grimsley of Washburn College I am thankful 

 for the specimens loaned to me, and to Mr. T. J. Titt of the same 

 college, I am much indebted for the descriptions and measure- 

 ments of the tusk fracrments. 



*Traus. Warner Free Institute of Science. Vol. 4, \). 15, (18'.)l3). 



