384 EXTINCT MAMMALIA OF NORTH AMERICA. 



All the fossil remains of Peccaries which have been described under the above 

 names, including the sjnonyma, I have considered as representing a genus distinct 

 from Dicotyles, founded upon differences in the degree of development of the constitu- 

 ent elements of the crown of the molar teeth. 



In Platygonus the principal lobes of the crown of the molar teeth are relatively 

 better developed than in Dicotyles. They are proportionately longer, less corrugated 

 at the sides, and approach somewhat in character the constituent lobes of the crown 

 of the corresponding teeth of the cervine family, while those of Dicotyles appear 

 more truly suilline in appearance. In other words, in comparing the molar teeth of 

 Platygonus with those of the living Peccaries, the Deer and the Hog, it will be ob- 

 served that the molars of the former resemble those of the Deer more than do the 

 molars of the Peccaries, while the latter resemble those of the Hog more than do the 

 molars of Platygonus. 



In the upper premolars of Platygonus, the crown is composed of a single pair of 

 transverse lobes, resembling those of the true molars, bounded by a basal ridge which 

 ia especially thick in front and behind. In the corresponding teeth of Dicotyles the 

 crowns are composed of four lobes, as in the true molars, but the posterior pair are 

 relatively less well developed, more especially the postero-internal one. 



Differences of the same character are observed in the lower premolars. In Platy- 

 gonus the crowns are composed of a transverse pair of principal lobes, bounded by a 

 narrow basal ridge in front, and a broad one behind. In Dicotyles the principal lobes 

 of the crown are less distinct, and in the last premolar the posterior basal ridge 

 assumes the character of an additional but less well developed pair of lobes, which 

 are not obvious in Platygonus. Quaternary. 



DICOTYLES. 



Dicotyles lenis. 



Dicotyles fossilis,Ijeidy : Holmes' Post-pliocene Fossils of South Carolina, 1860, 108, PI. XVII, 



Figs. 13, 14. 

 Dicotyles torquatus, "Wyman : Whitney's Eep. Geol. Surv. Up. Missis. Lead Region, 1862, 422. 



Cope : Proc. Ac. Nat. Sc. 1867, 138, 155 ; 1868, 185. 

 Squalodon protervvs, in part of Cope : Proc. Ac. Nat. Sc. 1867, 151. 

 Oynorca, in part of Cope : Proc. Ac. Nat. Sc. 1867, 151, 152. 



Remains of a Peccary, probably distinct from the living Dicotyles torquatus, have 

 been found in the post-pliocene formation of Ashley River, South Carolina, and in 

 Wisconsin. Recently Prof Cope has announced the discovery of remains of a Pec- 

 cary, with those of Ursvs amplidens, Equus, Tapirus, Cervus, etc., in a hard breccia 

 in Wythe Co., Virginia. 



The same author has also indicated the discovery of remains of a Peccary, found 

 together with those of an extinct species of Galera, in Charles County, Maryland. A 



